Gather all ingredients.

Rinse whole lettuce leaves and pat dry, being careful not to tear them; set aside.

Heat oil in a large skillet over medium-high heat. Add beef; cook and stir until browned and crumbly, 5 to 7 minutes. Transfer beef to a bowl and discard excess grease from the skillet.

Add onion to the same skillet and sauté until tender, 5 to 7 minutes.

Stir in hoisin sauce, garlic, soy sauce, vinegar, ginger, and chile pepper sauce until well combined. Add water chestnuts, green onions, sesame oil, and cooked beef; cook, stirring often, until the green onions just begin to wilt, about 2 minutes.

Transfer to a bowl. Arrange lettuce leaves around the outer edge of a large serving platter; place beef mixture in the center.