From allrecipes

16 Boston Bibb or butter lettuce leaves

1 pound lean ground beef

1 tablespoon cooking oil, such as grapeseeed

1 large onion, chopped

¼ cup hoisin sauce

2 cloves fresh garlic, minced

1 tablespoon soy sauce

1 tablespoon rice wine vinegar

2 teaspoons minced pickled ginger

1 dash Asian chile pepper sauce, or to taste (Optional)

1 (8 ounce) can water chestnuts, drained and finely chopped

1 bunch green onions, chopped

2 teaspoons Asian (dark) sesame oil

Directions

Rinse whole lettuce leaves and pat dry, being careful not tear them. Set aside.

Heat a large skillet over medium-high heat. Cook and stir beef and cooking oil in the hot skillet until browned and crumbly, 5 to 7 minutes. Drain and discard grease; transfer beef to a bowl. Cook and stir onion in the same skillet used for beef until slightly tender, 5 to 10 minutes. Stir hoisin sauce, garlic, soy sauce, vinegar, ginger, and chile pepper sauce into onions. Add water chestnuts, green onions, sesame oil, and cooked beef; cook and stir until the onions just begin to wilt, about 2 minutes.

Arrange lettuce leaves around the outer edge of a large serving platter and pile meat mixture in the center.