Marinate the chicken and refrigerate overnight.

Heat a grill pan well, then add the marinated chicken slices over high heat.

In another skillet, add 1 tablespoon of oil, then sauté the onions, followed by the bell peppers, then the tomatoes.

Once the vegetables are well sautéed, add them to the chicken, stir, and let them cook together for a few minutes to blend the flavors. For extra flavor, you can smoke the mixture with a piece of charcoal if desired.