In a large bowl, mix 1 cup sour cream, chicken, 1 cup cheese, 1/4 cup salsa, cilantro and cumin; set aside.
Pass tortillas through hot oil in shallow frying pan, using tongs, and place on plate.
Fill tortillas down the middle with 3 to 4 Tbsp. of mixture and place seam side down in a casserole dish. Cover enchiladas with remaining salsa (you may puree it and spread a thin layer to cover them completely).
Bake at 350 degrees for 30 minutes. Sprinkle with remaining cheese and bake an additional 5 minutes or until cheese is melted.
Garnish enchiladas with 1 cup shredded lettuce and 1 cup chopped tomato if desired and serve with remaining sour cream.