Wash and dry all produce. Preheat broiler to high or oven to 500 degrees with rack in upper position. Place flatbreads on a baking sheet and let warm in broiler or oven as it preheats. Remove once golden brown, 5-7 minutes. Meanwhile, bring a medium pot of salted water to a boil. Halve and peel onion, then cut into wedges. Core and seed bell pepper, then cut into strips. Slice squash into 1/2-inch-thick rounds. Mince or grate garlic.

Remove flatbreads from baking sheet and set aside. Toss squash, onion, and bell pepper with a large drizzle of oil. Place on same sheet, keeping each in their own section. Season with salt, pepper, and half the Tuscan heat spice. Broil or bake until tender and browned, 5-7 minutes. (TIP: Keep an eye out for any burning.) Set aside once done.

Once water boils, add gemelli to pot. Cook, stirring occasionally, until al dente, 9-11 minutes. Scoop out and reserve 1/4 cup pasta cooking water, then drain. Meanwhile, heat a drizzle of olive oil in a large pan over medium-high heat. Remove sausage from casings; discard casings. Add sausage to pan, breaking meat into pieces with a spatula or wooden spoon. Cook until browned and no longer pink, 4-6 minutes. Remove pan from heat.

Place flatbreads on another, lightly-oiled baking sheet. Spread 1/2 cup tomatoes evenly over flatbreads (save the rest for step 5). Season with salt and pepper. Tear mozzarella into small pieces with your hands and scatter over top. Evenly top flatbreads with half the sausage, half the onion, and all of the squash. Broil or bake until cheese melts and crust is crisp, 5-10 minutes. Cut flatbreads into slices and serve.

Heat a drizzle of oil in pot used for pasta over medium-high heat. Add garlic and remaining Tuscan heat spice. Cook until fragrant, about 1 minute. Add stock concentrate, reserved pasta cooking water, and remaining sausage and tomatoes. Simmer until reduced slightly, 1-2 minutes. Stir in gemelli, followed by 1 TBSP butter. After stirring in butter, stir in bell pepper and remaining onion. Season with salt and pepper, then remove pot from heat.

Divide pasta between two reusable containers. Divide Parmesan evenly and pack with containers, keeping it separate from the pasta. Keep refrigerated. When ready to eat, microwave pasta on high for 2-3 minutes. Sprinkle with Parmesan before enjoying.