Directions

1. Combine the ranch dressing, mayonnaise, and sour cream in a small bowl; add salt and pepper to taste and set aside.
2. Slice a 4-inch-wide “lobe” off the top of one head of lettuce (this will be one half of a lettuce “bun”). Slice 3 more lobes off the sides of the head. Repeat with the second head of lettuce; set the lettuce “buns” aside (save the remaining lettuce for another use).
3. Gently combine the turkey, Worcestershire, soy sauce, garlic powder, onion powder, salt, and pepper in a large bowl. Shape the mixture into four patties about 3/4-inch thick.
4. In a large nonstick skillet over medium heat, heat the oil. (Alternately, heat a grill pan over medium heat and use a paper towel dipped in the oil to lightly oil the grate.) Cook the patties until cooked through, about 4 minutes per side. During the last minute of cooking time, top each patty with a slice of cheese and cover the pan to help melt the cheese.
5. Place half of the lettuce “buns” on plates or a platter, cut side up. Top with the onion, patties, tomato, avocado, ranch sauce, and remaining “buns,” cut side down, and serve.