Step 1: Prepare the Vegetables and Feta
Preheat your oven to 400°F (200°C). Wash the red bell peppers, remove the stems and seeds, and cut them into large, 2-inch chunks. Peel the onion and cut it into thick wedges. Peel the garlic cloves but leave them whole.

Step 2: Arrange in the Baking Dish
Place the block of feta cheese in the center of a large baking dish (a 9×13 inch dish works perfectly). Arrange the chopped red peppers, onion wedges, and whole garlic cloves around the feta.

Step 3: Season and Roast
Drizzle everything generously with about 1/4 cup of the olive oil. Sprinkle the dried oregano, red pepper flakes (if using), salt, and black pepper over the vegetables and feta. Use your hands to toss the vegetables gently to ensure they are well-coated. Place the dish in the preheated oven and roast for 30-35 minutes. You’re looking for the peppers to be soft and slightly charred at the edges, and the feta to be soft and golden on top.

Step 4: Cook the Pasta
While the vegetables are roasting, bring a large pot of heavily salted water to a boil. Add the pasta and cook according to package directions until it is al dente (still has a slight bite). Before you drain the pasta, be sure to reserve at least 1 cup of the starchy cooking water. This water is liquid gold for your sauce.

Step 5: Blend the Sauce
Once the feta and vegetables are done roasting, carefully remove the baking dish from the oven. Transfer the entire contents of the dish—the softened feta, roasted peppers, onions, garlic, and any juices from the bottom of the pan—into a high-powered blender. Add the remaining 1/4 cup of olive oil.

Step 6: Create the Velvety Sauce
Blend the mixture on high speed until it is completely smooth and creamy. This may take 1-2 minutes. If the sauce seems too thick, you can add a splash of the reserved pasta water to the blender to help it move. The final consistency should be like a thick, pourable cream. Taste the sauce and adjust the seasoning with more salt and pepper if needed.

Step 7: Combine and Serve
Pour the beautifully blended roasted red pepper and feta sauce over your drained pasta. Add about 1/2 cup of the reserved pasta water to start. Stir everything together until every piece of pasta is coated in the luscious sauce. If the sauce is too thick for your liking, continue to add more pasta water, a little at a time, until it reaches your desired consistency.

Step 8: Garnish and Enjoy
Serve the pasta immediately, garnished with a generous amount of fresh, chopped basil or parsley and an extra sprinkle of black pepper or red pepper flakes.