In a large bowl, mix the shredded chicken, refried beans, salsa, cumin, onion powder, oregano, chili powder, shredded cheese, and chopped green onions.
Spoon about 1/2 cup of the chicken mixture onto the center of a tortilla. Fold the top and bottom edges over the filling, then fold in the sides and roll tightly.
Place the chimichangas seam side down on a baking sheet. Lightly brush each one with vegetable oil. Bake for 25 minutes at 400°F until golden and crispy.