Before starting, preheat your broiler to high. In a large pot, add 10 cups warm water and 2 tsp salt (use same for 4 ppl). Cover and bring to a boil over high heat. Wash and dry all produce. Cut cauliflower into bite-sized pieces. Add squash, cauliflower and 1 tbsp oil (dbl for 4 ppl) to a foil-lined baking sheet. Season with salt and pepper, toss to combine. Broil in the middle of the oven until golden-brown and tender, 12-15 min.

While squash and cauliflower cook, add cavatappi to the boiling water. Cook uncovered, stirring occasionally, until tender, 10-12 min. Reserve 1/4 cup pasta water (dbl for 4 ppl). Drain and return cavatappi to the same pot, off heat.

While cavatappi cooks, pat chicken dry with paper towels, then cut each tender in half crosswise. Season with garlic salt and pepper.

Heat a large non-stick pan over medium-high heat. When hot, add 1 tbsp butter (dbl for 4 ppl), then chicken. Cook, flipping occasionally, until cooked through, 5-6 min. (NOTE: Don't overcrowd the pan; cook the chicken in two batches if needed, using 1 tbsp butter per batch.)

Add onions to the pan with chicken. Cook, stirring occasionally, until softened, 1-2 min. Sprinkle with flour. Cook, stirring often, until coated, 1 min. Add cream and bring to a boil. Cook, stirring often, until thickened, 1 min.

Add chicken, cream sauce, cheddar cheese, reserved pasta water, half the squash and cauliflower and 1 tbsp butter (dbl for 4 ppl) to the pot with cavatappi. Stir until cheddar melts, 1 min. Divide between bowls, then top with remaining squash and cauliflower. Sprinkle with Parmesan and chili flakes, to taste.