Preheat the oven to 375 degrees F.
In a medium bowl, combine the chicken and salsa, and mix thoroughly. Cover and refrigerate for 15 minutes.
Remove chicken mixture from the refrigerator, and drain any excess liquid. Add cheese and taco seasoning, and mix to combine. This is your filling. Set aside.
Prepare a baking sheet by spraying it with nonstick spray. Set aside.
Dampen 2 paper towels, and place tortillas between them. Microwave for about 1 minute, until tortillas are warm and pliable.
Place one tortilla flat on a clean dry surface (keep the rest between the paper towels), and spoon about 2 heaping tablespoons filling onto the tortilla. Spread it evenly across the entire surface, and roll the tortilla up tightly, so that you have a cigar-shaped tube. Secure with toothpicks, if needed, and place seam-side down on the baking sheet. Repeat with remaining tortillas and filling.
Bake in the oven until crispy, 14 to 16 minutes.
Allow to cool for 5 minutes. Serve with sour cream and additional salsa for dipping, if using. Enjoy!