Heat the oil in a skillet. Sauté the onion with the garlic and red bell pepper. Add and cook for 2 minutes: jalapeños, cumin, chili powder, oregano, and salt. Add the cooked chicken, black beans, and tomato purée or sauce. Stir well and cook until heated through. Let cool.

Once cooled, mix in the cilantro and green onions. Lay the flour tortillas on the table and divide the filling evenly among the 10 tortillas, spreading it in the center.

Fold the bottom and top toward the center to seal. Preheat the oven to 420°F (215°C).

In a skillet, heat 1/4 cup oil. Fry the tortillas on both sides until golden brown, then place them on a baking sheet. Heat the chimichangas in the oven for about 15 minutes, being careful not to burn them.