Step 1

Preheat grill for medium heat and lightly oil the grate.

Step 2

Grill tomatoes, bell peppers, and onion halves on the preheated grill until well charred, about 15 minutes. When peppers are cool enough to handle, split with a knife and remove seeds.

Step 3

Heat olive oil in a large skillet; cook and stir garlic until fragrant, about 1 minute. Stir canned crushed tomatoes, basil, grilled tomatoes, bell peppers, and onion into skillet; bring to a boil, reduce heat, and simmer until vegetables are tender, about 10 minutes. Puree vegetable mixture with a stick blender; season with salt and pepper and keep at a simmer.

Step 4

Bring a large pot of water to a boil; drop in summer squash and zucchini spirals and cook until tender, about 3 minutes. Drain water from pot; lay spirals on paper towels to drain completely.

Step 5

Place squash spirals on individual plates; top with a portion of cooked chicken, a generous amount of red pepper sauce, and Parmesan cheese.