Preheat the oven to 400°F.

Chop onion and sauté for 2-3 minutes in a heated pan.

Add chopped garlic and mushrooms sauté until onion is translucent and mushrooms are cooked. Set aside.

Chop carrots, zucchini, and sweet potatoes in bite-size pieces. Also, chop the broccoli into florets.

Bring those vegetables to boil or steam for 10 minutes (not the red pepper or cherry tomatoes). They don’t need to be totally cooked, the cooking will finish in the oven.  Set aside to cool and dry off.  

For the cheese sauce, place all the ingredients into a saucepan on low heat stirring continuously until you get a thick-cheesy sauce.

Place all the vegetables (including now the red pepper and cherry tomatoes) on a baking sheet, drizzle with the oil, and season with salt and pepper.

Roast the vegetables in the oven for 10-15 minutes until the red pepper and tomatoes are tender.  Then remove the vegetables from the oven.

Coat the veggies with the cheesy sauce and place them into a casserole dish.  Place them back into the oven to cook until everything is fork-tender.

Optional: sprinkle the top of the casserole dish with bread crumbs before putting it in the oven for a crunchy au gratin.