In a bowl stir flour into sour cream. Add 1/2 cup of the shredded cheese, the chili peppers, and milk; mix well. Spray a 9-inch pie plate with nonstick coating. Place one tortilla in the plate.
Top with about 2/3 cup of the thawed Mexican Meat Mix and one-third of the sour cream mixture. Repeat with another tortilla, another 2/3 cup Mexican Meat Mix, and another third of the sour cream mixture. Cover with remaining tortilla, remaining Mexican Meat Mix, and remaining sour cream mixture.
Bake, uncovered, in a 350 degree F oven for 25 to 30 minutes or until heated through. Sprinkle remaining 1/4 cup cheese over pie. Let stand 5 minutes before cutting into wedges to serve. Serve with shredded lettuce, tomato wedges, and if desired, avocado wedges. Makes 4 servings.