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.
Bake for 20 minutes and serve.