Line a rimmed baking sheet with tin foil and coat with cooking spray. Set aside.
Clean and prepare your vegetables for roasting (make sure to peel the brussels sprouts if needed). Cut vegetables (except sweet potatoes and brussels sprouts) into bite sized pieces.
Peel the washed sweet potatoes and cut into ¾ inch cubes.
In a large bowl, toss together sweet potatoes, onion, bell pepper, rosemary, garlic, carrots, green beans, mushrooms, Italian seasoning, pepper, oil and butter. A.dd one tablespoon of oil at a time until all the vegetables are coated.
Pour out onto one side of the lined baking sheet. Sprinkle with salt and place sprigs of rosemary (or your favorite herb) on top and set aside.
Cut brussels sprouts in half and mix them in that same bowl with oil. Pour out onto the other side of your baking sheet. Sprinkle with pepper and sea salt.
Bake at 400 for 35 to 45 minutes, or until potatoes are crisp tender with some charred edges and tips. Exact timing will depend on the size of your vegetable pieces and chunks.
After 15 to 20 minutes of cooking, stir and mix vegetables so that all sides are cooked throughout.
Serve with rice or as desired. Enjoy!