Heat olive oil in a large skillet over medium-high heat.
Add ground chicken and season with salt and pepper, or chunked-up chicken breasts
Brown and crumble chicken, about 3-5 minutes, drain fat. Or cook chicken breast chunks, and drain fat.
After draining, return to heat and stir in garlic, onion, hoisin sauce, oyster sauce, soy sauce, rice wine vinegar, ginger, and chili paste and cook until onions have become translucent, about 2-3 minutes.
Stir in chestnuts and green onions cooking until tender, about 1-2 minutes;
Taste and season with salt and pepper, to preference.
spoon several tablespoons of the chicken mixture into the center of a lettuce leaf and enjoy