Heat 2 tsp oil in a large skillet set over medium-high heat. Add onion and bell pepper and saute 3-4 minutes, until golden and tender. Add garlic and saute 30 seconds, until fragrant.
Add in tomato sauce, chicken broth, salsa, cumin, paprika, cayenne, salt and pepper to taste. Bring to a low boil, then reduce heat and simmer for 5-6 minutes, stirring frequently until sauce has thickened and reduced by half. Taste and adjust seasonings, if necessary. Stir in sour cream, chicken, and corn; mix well and remove from heat, then allow to cool slightly.
Spread a heaping ¼ cup refried beans onto the center of each tortilla, then top with ½ cup of the chicken mixture. Flatten the filling into rectangle shape with the back of a spoon, then top with 3 tablespoons shredded cheese. Fold the bottom of the tortilla snugly over the filling, then fold in the sides. Roll the chimichanga up to the top edge, forming a tight cylinder, and secure the ends with wooden toothpicks. Repeat with the remaining ingredients.
Fill a pot or heavy skillet with about 1-inch of cooking oil and heat over medium-high heat to 365 degrees F. Place two chimichangas flap side down in the hot oil and cook 1-2 minutes of each side until golden brown.
Remove and drain on paper towels, and remove toothpicks. Repeat frying with remaining chimichangas.