Preheat the oven to 350°F. Spray a 9x13 pan with cooking spray and set aside.
Mix the chicken with 1 cup of the cheese. Place a couple spoon fulls of the chicken mixture in each tortilla, roll up and place seam-side down in the prepared pan.
In a medium sauce pan, melt the butter over medium heat. Whisk in the flour and cook for a about a minute, whisking the whole time. Add broth and whisk until smooth, heat for 3-4 minutes until thick and bubbly. Remove from the heat and stir in the sour cream and salsa. Pour the sauce over the rolled tortillas and top with the remaining cheese.