Preheat oven to 425 degrees. Line two 15 x 10-inch baking sheets with nonstick aluminum foil or aluminum foil sprayed with cooking spray.
Place the riced cauliflower on one of the prepared baking sheets and add the carrots. Drizzle with 1-2 tablespoons olive oil and season with salt and black pepper to taste. Stir the cauliflower and carrots to distribute the oil and seasonings.
Place the zucchini, yellow squash and red bell pepper on the second baking sheet. Drizzle with 1-2 tablespoons olive oil and season with salt and black pepper to taste. Stir to distribute the oil and seasonings.
Place both sheet pans with the vegetables in the oven and roast for 12 minutes.
Remove both sheet pans from the oven. Tent the cauliflower / carrot sheet pan with aluminum foil to keep it warm or place another identical-sized sheet pan over it to keep it warm.
Add the minced garlic to the zucchini / yellow squash / red bell pepper sheet pan and stir to distribute.
Place the zucchini / yellow squash/ red bell pepper sheet pan back in the oven for 4-5 minutes.
Combine both sheet pans of vegetables, stir well and adjust seasoning as desired.
Add the Parmesan cheese and parsley. Serve immediately.