1 can (8-ounce size) sliced water chestnuts -- drained, finely chopped
1 bunch green onions -- thinly sliced
2 teaspoons Asian sesame oil
Rinse lettuce leaves, keeping them whole. Set aside to drain.
Cook chicken in a large skillet over medium heat, stirring often to break up the meat. Add onion, garlic, soy sauce, hoisin sauce, ginger, vinegar, and chili sauce. Cook until the meat is crumbled and brown. Add water chestnuts, pine nuts and green onions. Cook until onions begin to wilt, about 2 minutes.
Stir in sesame oil. Arrange lettuce leaves on the outer edge of a platter. Spoon meat mixture in center. Allow diners to spoon meat mixture into lettuce leaves and eat like a taco.
*You can use 1/8 teaspoon cayenne pepper or 1/2 teaspoon dried red chili flakes instead.