Rice also makes a great accompanying filling for these lettuce wraps.
Step 2
Combine cucumber and vinegar in bowl; set aside. Combine mayonnaise and Sriracha in second bowl; set aside. Combine soy sauce, sugar, garlic, and oil in third bowl.
Step 3
Cook beef in 12-inch nonstick skillet over high heat until any juices have evaporated and beef begins to fry in its own fat, 8 to 10 minutes. Add soy sauce mixture to skillet and cook until nearly evaporated, about 2 minutes. To serve, fill lettuce leaves with beef mixture and top with pickled cucumbers and Sriracha mayonnaise.