Oat–Black Bean Burgers

If you are vegetarian, or simply don't want to eat meat all the time, this burger is for you!
Sauté 1 diced small onion, 1 diced carrot and 2 cups sliced cremini mushrooms in 2 tablespoons olive oil in a large skillet over medium-high heat until browned, 6 minutes. Stir in 2 teaspoons chili powder and one 14-ounce can black beans (drained); season with salt and pepper. Pulse in a food processor with 1 cup quick-cooking oats until combined, then form into 4 patties. Refrigerate 1 hour. Dust both sides with flour and cook in vegetable oil in a large nonstick skillet over medium-high heat until browned, 3 to 4 minutes per side. Serve on buns with toppings.