Preheat oven to 450°F. Clean and cut up an assortment of vegetables such as carrots, bell peppers, onions, zucchini, eggplant, mushrooms, Brussels sprouts, asparagus and butternut squash. Toss vegetables with olive oil, salt and pepper and place on a baking sheet. Roast vegetables in oven until tender and edges start to brown, about 45 minutes. Flip once or twice during roasting. Keep in fridge for up to 4 days or freeze for up to 3 months.