In a skillet over medium heat, sauté the diced onions and sliced bell peppers for about five minutes until softened. Stir in the cooked chicken or beans and half the cilantro; season with a pinch of salt and pepper.

In another skillet, warm one tortilla on low heat. Sprinkle half the shredded Monterey Jack and sharp cheddar cheese on one side, allowing it to melt slightly before adding the filling.

Once the cheese begins to melt (about a minute), layer the filling on top. Sprinkle a bit more cheese over the filling and fold the tortilla in half.

Cook for about two minutes on each side until golden brown and crispy. Use a spatula to flip gently.

Remove from heat, let cool briefly, slice into wedges, and serve with a dollop of sour cream on the side.