Combine enchilada sauce and chopped tomatoes in a medium saucepan. Cook over medium heat until mixture boils. Reduce heat and simmer. Heat oil over medium-high heat in a small skillet. Dip one tortilla at a time in hot oil for several seconds, then dip in hot enchilada sauce mixture. Set aside. Heat 'Mexican Meat Mix' in a saucepan. Place about 1/4 cup 'Mexican Meat Mix' on each tortilla and sprinkle with 2 Tablespoons grated Cheddar cheese. Roll up and place close together in a shallow casserole dish, seam-side down. Pour remaining sauce over enchiladas. Sprinkle with additional grated cheese. Bake about 15 minutes, until bubbly. Spoon sour cream over enchiladas and serve hot.