Warming Irish Stew with Lentils and Mushrooms

If you ask me, Irish stew is one of those meals that just feels like a warm hug.

This hearty vegetarian version swaps out the traditional lamb for lentils and mushrooms, creating a filling dinner that’s perfect for cold nights. The earthy lentils and meaty mushrooms pair with tender potatoes and carrots in a rich Guinness broth.

It’s flavored with thyme and rosemary, then simmered until everything is soft and the flavors meld together. A sprinkle of fresh parsley and some crusty bread help the whole thing come together.

It’s a comforting dish that works great for feeding a hungry family, especially when you want something that sticks to your ribs.

What Kind of Lentils Should I Use?

For this Irish stew, brown or green lentils are your best bet since they hold their shape well during the longer cooking time and won’t turn mushy. French green lentils, also called Puy lentils, are especially great if you can find them – they have a slightly peppery flavor and stay firm even after simmering. Red or yellow lentils aren’t ideal here because they break down quickly and will turn your stew into more of a thick porridge. Before adding them to the pot, give your lentils a quick rinse in a strainer to remove any dust or debris, and don’t worry about soaking them beforehand since they’ll cook perfectly fine right in the stew.

Options for Substitutions

This stew is pretty forgiving when it comes to swaps, so here are some options if you need to make changes:

• Irish stout beer: If you don’t have stout or prefer not to use alcohol, replace it with an equal amount of vegetable broth plus 1 tablespoon of balsamic vinegar and 1 teaspoon of molasses to mimic that dark, rich flavor.
• Lentils: Green or brown lentils work best here since they hold their shape during cooking. Red lentils will turn mushy, so avoid those unless you want a thicker, porridge-like texture.
• Mushrooms: Any mushroom variety works – button, cremini, portobello, or a mix. If you’re not a mushroom fan, you can leave them out or add extra carrots and celery instead.
• Potatoes: Russet, Yukon gold, or red potatoes all work well. Just cut them into similar-sized chunks so they cook evenly.
• Flour: For a gluten-free version, swap the flour with cornstarch (use 2-3 tablespoons) or arrowroot powder in the same amount.
• Fresh herbs: Don’t have fresh parsley? Dried parsley works fine (use about 2 teaspoons), or swap it with fresh cilantro or chives for a different flavor profile.

Watch Out for These Mistakes While Cooking

The biggest mistake when making this stew is adding the flour without cooking it properly – make sure to stir it constantly for at least a minute after adding it to avoid a raw flour taste and ensure your stew thickens correctly.

Another common error is not scraping the bottom of the pot well after adding the stout, which can lead to burnt bits sticking and giving your stew a bitter flavor, so use a wooden spoon to really get in there.

Don’t skip checking your lentils and potatoes at the 45-minute mark, as different varieties cook at different rates – if your potatoes are tender but the lentils are still hard, add a bit more broth and keep simmering.

For extra depth of flavor, let your vegetables cook until they start to brown slightly before moving to the next step, and if your stew seems too thin at the end, simmer it uncovered for an extra 10-15 minutes to reduce the liquid.

What to Serve With Irish Stew?

This hearty stew is pretty much a complete meal on its own, but I love serving it with thick slices of crusty bread for soaking up all that rich, beer-infused broth. A simple side salad with mixed greens and a light vinaigrette helps balance out the heartiness of the stew, or you could go with some buttered cabbage or roasted Brussels sprouts to keep things in the Irish comfort food zone. If you’re feeding a crowd, consider putting out some extra bread and butter on the table – people always seem to want more for dipping. For a cozy dinner, a pint of the same stout beer you used in the stew makes a great pairing too.

Storage Instructions

Store: This stew actually gets better after a day or two in the fridge! Keep it in an airtight container for up to 5 days. The lentils will soak up more of those rich flavors, making it even tastier the next day.

Freeze: Irish stew freezes really well for up to 3 months. Let it cool completely, then portion it into freezer-safe containers. Just note that the potatoes might get a bit softer after freezing, but the flavor stays great.

Reheat: Warm it up on the stovetop over medium-low heat, stirring occasionally until heated through. You might need to add a splash of vegetable broth or water since the lentils tend to absorb liquid as they sit. In the microwave, heat on medium power and stir halfway through.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1750-1950
• Protein: 55-65 g
• Fat: 30-36 g
• Carbohydrates: 320-350 g

Ingredients

For the stew:

• 2.5 tbsp olive oil (I prefer Bertolli for a clean, neutral flavor)
• 4 carrots
• 1 large onion
• 10 oz mushrooms (sliced into 1/4-inch pieces for even cooking)
• 4 garlic cloves
• 1/3 cup tomato paste (I use Hunt’s to add a deep, rich color)
• 1/3 cup flour
• 2 tsp thyme
• 1 tsp dried rosemary
• 1.5 tsp salt
• 1/4 tsp pepper
• 12 oz stout (Guinness is classic and adds the best malty depth)
• 5 potatoes (peeled and cut into 1-inch chunks)
• 1.25 cup lentils
• 4.5 cups vegetable broth

For serving:

• 3 tbsp parsley
• bread

Step 1: Prepare All Ingredients (Mise en Place)

• 5 potatoes
• 4 carrots
• 1 large onion
• 10 oz mushrooms
• 4 garlic cloves
• 1.25 cup lentils
• 1/3 cup tomato paste
• 1/3 cup flour
• 2 tsp thyme
• 1 tsp dried rosemary
• 1.5 tsp salt
• 1/4 tsp pepper
• 12 oz stout

Peel and cut potatoes into 1-inch chunks, peel and slice carrots into rounds about 1/4-inch thick, dice the onion into medium pieces, slice mushrooms into 1/4-inch pieces, and mince garlic cloves.

Measure out the lentils, tomato paste, flour, dried herbs, salt, pepper, and stout.

Having everything prepped and ready will make the cooking process smooth and allow you to focus on building flavor.

Step 2: Sauté Aromatics and Build Flavor Base

• 2.5 tbsp olive oil
• 4 carrots
• 1 large onion

Heat the olive oil in a large pot or Dutch oven over medium heat.

Add the diced onion and carrot slices, stirring occasionally, and cook for about 6 minutes until they begin to soften and the onion becomes translucent.

This initial sauté develops sweetness in the vegetables and creates a flavor foundation for the entire stew.

Step 3: Add Mushrooms, Garlic, and Tomato Paste

• 10 oz mushrooms
• 4 garlic cloves
• 1/3 cup tomato paste

Stir in the sliced mushrooms, minced garlic, and tomato paste, cooking for about 4 minutes until the mushrooms release their moisture and the mixture becomes fragrant.

The tomato paste will start to caramelize slightly against the pot bottom, adding deep umami richness—I find this moment is crucial for developing the stew’s complex flavor profile.

Step 4: Create the Flour and Herb Blend

• 1/3 cup flour
• 2 tsp thyme
• 1 tsp dried rosemary
• 1.5 tsp salt
• 1/4 tsp pepper

Sprinkle the flour over the vegetable mixture and stir constantly for about 1 minute to coat everything evenly.

This flour will act as a thickener for the stew.

Add the dried thyme, rosemary, salt, and pepper, stirring well to distribute the herbs throughout.

The flour coating allows the starch to cook out and thicken the liquid later without creating lumps.

Step 5: Deglaze with Stout

• 12 oz stout

Pour in the stout and use a wooden spoon to scrape up any browned bits stuck to the bottom of the pot—this deglazing step releases concentrated flavors that would otherwise be wasted.

The alcohol will cook off during simmering, leaving behind the malty depth that makes a proper Irish stew so distinctive.

Step 6: Build the Stew and Simmer

• 5 potatoes
• 1.25 cup lentils
• 4.5 cups vegetable broth

Add the prepared potatoes and lentils, then pour in the vegetable broth.

Bring the mixture to a boil over medium-high heat, then reduce to medium-low and simmer uncovered for 45 minutes, stirring occasionally.

The potatoes and lentils will become tender and begin to break down slightly, thickening the stew naturally while the flavors meld together.

I like to start checking the potatoes around the 40-minute mark—they should be fork-tender but not falling apart.

Step 7: Adjust Consistency and Finish

• 3 tbsp parsley
• bread

Once the potatoes and lentils are tender, taste the stew and adjust seasoning if needed.

If the stew seems too thick, add more broth a splash at a time; if it’s too thin, simmer uncovered for another 10-15 minutes to reduce.

Stir in the fresh parsley just before serving for brightness and color.

Serve in bowls with crusty bread alongside for soaking up the rich, flavorful broth.

Warming Irish Stew with Lentils and Mushrooms

Delicious Warming Irish Stew with Lentils and Mushrooms recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 25 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr 10 minutes mins

Servings: 6 servings

Calories: 1850

Ingredients Method

Ingredients

  

For the stew::

• 2.5 tbsp olive oil (I prefer Bertolli for a clean, neutral flavor)
• 4 carrots
• 1 large onion
• 10 oz mushrooms (sliced into 1/4-inch pieces for even cooking)
• 4 garlic cloves
• 1/3 cup tomato paste (I use Hunt's to add a deep, rich color)
• 1/3 cup flour
• 2 tsp thyme
• 1 tsp dried rosemary
• 1.5 tsp salt
• 1/4 tsp pepper
• 12 oz stout (Guinness is classic and adds the best malty depth)
• 5 potatoes (peeled and cut into 1-inch chunks)
• 1.25 cup lentils
• 4.5 cups vegetable broth

For serving::

• 3 tbsp parsley
• bread

Method

 

1. Peel and cut potatoes into 1-inch chunks, peel and slice carrots into rounds about 1/4-inch thick, dice the onion into medium pieces, slice mushrooms into 1/4-inch pieces, and mince garlic cloves. Measure out the lentils, tomato paste, flour, dried herbs, salt, pepper, and stout. Having everything prepped and ready will make the cooking process smooth and allow you to focus on building flavor.
2. Heat the olive oil in a large pot or Dutch oven over medium heat. Add the diced onion and carrot slices, stirring occasionally, and cook for about 6 minutes until they begin to soften and the onion becomes translucent. This initial sauté develops sweetness in the vegetables and creates a flavor foundation for the entire stew.
3. Stir in the sliced mushrooms, minced garlic, and tomato paste, cooking for about 4 minutes until the mushrooms release their moisture and the mixture becomes fragrant. The tomato paste will start to caramelize slightly against the pot bottom, adding deep umami richness—I find this moment is crucial for developing the stew's complex flavor profile.
4. Sprinkle the flour over the vegetable mixture and stir constantly for about 1 minute to coat everything evenly. This flour will act as a thickener for the stew. Add the dried thyme, rosemary, salt, and pepper, stirring well to distribute the herbs throughout. The flour coating allows the starch to cook out and thicken the liquid later without creating lumps.
5. Pour in the stout and use a wooden spoon to scrape up any browned bits stuck to the bottom of the pot—this deglazing step releases concentrated flavors that would otherwise be wasted. The alcohol will cook off during simmering, leaving behind the malty depth that makes a proper Irish stew so distinctive.
6. Add the prepared potatoes and lentils, then pour in the vegetable broth. Bring the mixture to a boil over medium-high heat, then reduce to medium-low and simmer uncovered for 45 minutes, stirring occasionally. The potatoes and lentils will become tender and begin to break down slightly, thickening the stew naturally while the flavors meld together. I like to start checking the potatoes around the 40-minute mark—they should be fork-tender but not falling apart.
7. Once the potatoes and lentils are tender, taste the stew and adjust seasoning if needed. If the stew seems too thick, add more broth a splash at a time; if it's too thin, simmer uncovered for another 10-15 minutes to reduce. Stir in the fresh parsley just before serving for brightness and color. Serve in bowls with crusty bread alongside for soaking up the rich, flavorful broth.