- To bake in oven, heat oven to 425°F. Melt butter in 10-inch no-stick skillet over medium high heat until sizzling; add onion, peppers and garlic. Continue cooking, stirring constantly, 4-6 minutes or until vegetables are crisply tender. Stir in beef strips, chili powder, cumin and salt. Continue cooking, stirring constantly, 1-2 minutes or until mixture is heated through. Place flatbreads on large ungreased baking sheet. Divide meat mixture evenly among breads. Top with cheese strips and cilantro, if desired. Bake 7-9 minutes or until cheese is melted and bubbly.