In a large mixing bowl, combine the shredded chicken, cheddar cheese, sour cream, green onions, cumin, chili powder, salt, and pepper. Mix until all ingredients are well blended.

Place a large frying pan or pot on medium heat and add the vegetable oil. Allow the oil to heat up; it should reach about 350°F (175°C).

Take one flour tortilla and add about 1/2 cup of the chicken mixture in the center. Fold the sides of the tortilla inward, then roll it up tightly from the bottom to secure the filling.

Repeat the process with the remaining tortillas and filling mixture.

Once the oil is hot, carefully place one or two chimichangas into the oil, avoiding overcrowding. Fry them for about 3-4 minutes on each side or until they are golden brown and crispy.

Use a slotted spoon to remove the chimichangas from the oil and place them on a paper towel-lined baking sheet to drain excess oil.

Continue frying the remaining chimichangas until they are all cooked.

Serve the chimichangas hot, topped with your choice of guacamole, salsa, or additional sour cream.

For a healthier option, you can bake the chimichangas instead of frying them. Brush them lightly with oil and bake at 400°F (200°C) for about 20-25 minutes or until golden brown.

Feel free to customize the filling with black beans, corn, or peppers for additional flavor and texture.