Bring a large pot of salted water to a boil. While waiting, prepare all your vegetables: cut the red and yellow bell peppers into 1-inch squares, cut the aubergine and courgette into similar-sized chunks, quarter the mushrooms, and cut the onion into 1-inch wedges. Mince the garlic and set aside. Once the water boils, add the pasta and cook according to package directions until al dente, then drain and set aside to cool slightly.
While the pasta cooks, preheat your oven to 200°C (390°F). Place all the prepared vegetables in a large bowl and toss with 2 tablespoons of olive oil, 1/2 teaspoon salt, 1/4 teaspoon pepper, and the Italian seasoning until evenly coated. Spread them in a single layer on a baking sheet and roast for 20-25 minutes, stirring halfway through, until the vegetables are tender and lightly caramelized at the edges. I like to roast the veggies until they have some golden-brown spots—it brings out their natural sweetness and adds depth to the salad.
While the vegetables roast, prepare the dressing. In a small bowl, whisk together 1/4 cup olive oil, the juice of 1 lemon, 1 tablespoon honey, 1/2 tablespoon balsamic vinegar, the minced garlic from Step 1, 1/4 teaspoon red pepper flakes, and a pinch of salt and pepper. Taste and adjust seasonings as needed. I find that freshly minced garlic in the dressing really makes a difference—it stays vibrant and aromatic rather than overpowering the other flavors.
In a large serving bowl, combine the cooled pasta from Step 1 with the roasted vegetables from Step 2. Pour the dressing from Step 3 over the mixture and toss well until all the pasta and vegetables are evenly coated. Add the feta crumbles and gently fold them in, being careful not to break them apart too much. Finish with 2 tablespoons of fresh parsley scattered over the top and toss one final time to incorporate.