In a large bowl, add 2 cups cooked chicken (chopped or shredded), 1 can refried beans, 1/2 cup salsa, 1 teaspoon cumin, 1/2 teaspoon dried oregano (crushed), 1 teaspoon chili powder, 1 cup shredded cheese, and 2 chopped green onions. Stir until evenly combined.
Lay out the 6 large flour tortillas on a clean surface. Spoon about 1/2 cup of the chicken mixture into the center of each tortilla.
Fold the left and right sides of each tortilla over the filling, then roll the tortilla from one open end to the other to form a sealed roll. Place each rolled chimichanga seam-side down on the work surface.
Decide how you want to cook the chimichangas (baked or pan-fried).
For baked chimichangas: preheat the oven to 400°F. Arrange the seam-side down chimichangas on a baking sheet (use foil or parchment if you like). Brush each chimichanga lightly with the 3 tablespoons oil (vegetable or canola). Bake for about 25 minutes, until the tortillas are golden and crispy.
For pan-fried chimichangas: heat a skillet over medium heat. Add some of the 3 tablespoons oil to coat the bottom of the skillet. When the oil is hot, place chimichangas seam-side down in the skillet. Turn them gently every 1–2 minutes so all sides become golden and crisp, cooking until heated through and evenly browned.
If pan-fried, drain briefly on paper towels to remove excess oil. Serve the chimichangas warm, topped or served with salsa, sour cream, and guacamole if desired.