Toss together 2.5 cups cheese and flour. Saute' onion in butter. Remove from heat; stir in cheese mixture. Brown meat; drain. Add tomato sauce, beans and seasonings; simmer 10 minutes. Dip each tortilla in hot oil to soften. Place approximately quarter cup cheese mixture on each tortilla; roll up tightly. Place seam side down in an 11.75 X 19 cm baking dish. Cover with meat mixture. Cover dish with aluminum foil; bake at 180ºC degrees, 20-25 minutes or until heated through. Top with remaining cheese.