In skillet cook onion in 2 tablspoons oil till tender but not brown. Blend in flour. Add milk, chili peppers, and salt. Cook, stirring constantly, till thickened and bubbly. Stir in beef and tomatoes. Heat through; keep warm. In small skillet heat 2 tablespoons oil. Holding tortilla with tongs, dip in hot oil for 10 seconds or till limp. Drain on paper toweling. Place a hot tortilla in 9x9x2-inch baking pan. Top with about 1/4 cup beef mixture and 2 tablespoons of cheese. Layer on remaining tortillas, beef mixture, and cheese to make a stack. Bake in 350 oven for 20 minutes or till hot. Unstack to serve. Serves 4. Posted to Bakery Shoppe Digest149 by Sandra Swinford on Jul 7, 1997