Two classic dishes come together in this epic dinner. Chili powder and cumin—aka, classic Tex-Mex spices—flavor the patties, which are then topped with sautéed bell peppers and onions. A quick avocado spread adds creaminess and flavor. For a cheeseburger, try slices of pepper Jack atop the patties, or tuck some cotija into the center of each patty before cooking. Though the fajita burgers are filling as is, a side salad of romaine with a lime vinaigrette would be welcome, as would a dish of queso and chips.