1 1/2 lb. boneless beef chuck shoulder steak
1 med. onion, chopped
1 (1 1/4 oz.) pkg. taco seasoning mix
1 tsp. salt
2 c. water
1/2 tsp. pepper
4 (8 inch) flour tortillas
1 med. avocado
1 sm. tomato
8 oz. sour cream
9 tbsp. salad oil

About 3 hours before serving: In 5-quart Dutch oven over medium-high heat, in 1 tablespoon hot salad oil, cook chuck steak until well browned on both sides. Add onion, taco seasoning mix, salt, pepper and 2 cups water. Over high heat, heat to boiling. Reduce heat to low; cover and simmer 1 1/2 to 2 hours until meat is very tender and falls apart when tested with a fork.

When meat is done, increase heat to medium and cook, uncovered, until liquid has evaporated. With 2 forks, pull meat, in Dutch oven, into shreds. Keep warm.

In 10-inch skillet over medium-high heat, in 1 tablespoon hot salad oil, cook 1 tortilla until lightly browned and puffy on both sides. Remove tortilla to cookie sheet; keep warm. Repeat with remaining tortillas, using 1 tablespoon salad oil for each.

Cut avocado lengthwise in half; remove peel and seed. chop avocado. Chop tomato. Spread 1/4 of sour cream on each tortilla.

On serving plate, place one tortilla, sour cream side up. Top with 1/3 of meat mixture, then 1/4 of chopped avocado. Repeat layering twice. Place the 4th tortilla, sour cream side up, on top. Sprinkle with chopped tomato and remaining avocado. Makes 6 main dish servings, about 600 calories per serving.