Heat oven to 350~. Grease a large cookie sheet. In large skillet, cook onion and garlic in oil until onion is tender. Add chicken; cook over low heat until thoroughly heated, stirring occasionally. Remove from heat. Separate dough into 8 rectangles; firmly press perforations to seal. Spread 2 t of the salsa on each rectangle to within 1/2 inch of edge. Stir 1 cup of the cheese into chicken mixture. Spoon heaping 1/3 cup of chicken mixture onto half of each rectangle. Starting at shortest side or rectangle topped with chicken, roll up; firmly pinch ends to seal. Place the seam side down on the greased cookie sheet. Bake at 350 for 16 to 21 minutes or until golden brown. Remove from oven; top each with about 2 T. of remaining cheese. Return to oven. Bake an additional 1 to 2 minutes or until cheese is melted. Serve with sour cream and additional salsa.