How to Make It
Heat 2 tablespoons sesame oil in a large nonstick skillet over medium-high. Add garlic and onion to pan, stirring until softened, about 3 minutes. Add vegetarian beef and allow to warm through, about 2 minutes. Stir in chestnuts and mushrooms; cook for 5 minutes.
Meanwhile, whisk together hoisin sauce, soy sauce, ginger, hot sauce, vinegar, lime juice, salt, and pepper in a small bowl. Reduce heat to medium-low and add hoisin sauce mixture to pan; let simmer for 10 minutes. Stir in green onions; cook for an additional 2 minutes.
Divide mixture evenly among 8 lettuce leaves. Serve each topped with about ½ teaspoon sesame seeds.