Guacamole Burger

Serves 12.
1 tablespoon Worcestershire sauce
1 tablespoon salt
1/2 tablespoon pepper
1 1/2 pounds lean ground beef
4 onions, sliced
4 tomatoes
3 California avocados, seeded, peeled and mashed
Lettuce leaves as needed 12 sesame burger buns .
Combine Worcestershire, salt, pepper, and ground beef. Shape into 12 patties. Refrigerate at least 30 minutes.
Broil, grill, or pan fry to desired doneness. Serve on bun with lettuce, sliced tomatoes, and onion.
Place approximately 2 ounces of California mashed avocado on top and serve.