Heat oven to 500 degrees F and roast red peppers on a baking sheet until charred – about 25-30 minutes. Cover in foil for 10 minutes to steam, then gently peel away the charred skin, seeds and stems. Set aside.
While the red peppers are roasting, bring a large skillet over medium heat and sauté shallots, onion and garlic in 2-3 tablespoons olive oil until golden brown and soft, about 4-5 minutes. Season with a generous pinch of salt and pepper, then remove from heat, and transfer to a blender. Add the roasted peppers, milk, red pepper flakes and flour to the blender.
Blend until creamy and smooth, taste and adjust seasonings as needed, adding more salt and pepper or red pepper flakes, as needed. When the taste is to your liking, pour the sauce back into the skillet and simmer it over medium low heat until it thickens enough to coat the back of a wooden spoon.
While the sauce simmers, cook the pasta according to the directions on the package. If you’re using spiralized zucchini, start preparing it now.
Once sauce is thickened to desired consistency turn heat to low, and add noodles (or zucchini), a drizzle of more olive oil and a pinch of salt and pepper. Toss to coat the noodles (or zucchini).
Serve with Parmesan, red pepper flakse and fresh chopped basil.
Inspired by Minimalist Baker