01 -
In a small bowl, whisk together 3 tablespoons hoisin sauce, soy sauce, rice vinegar, and toasted sesame oil. For a glossy, thicker consistency, whisk in cornstarch if using. Set mixture aside near the cooktop.
02 -
Heat 1 teaspoon vegetable oil in a large skillet over medium heat until shimmering. Add ground chicken and cook, breaking up into small pieces, until completely cooked and no longer pink, about 7 to 8 minutes. Transfer the chicken to a clean bowl and set aside.
03 -
Add remaining 1 teaspoon vegetable oil to the same skillet. Add finely chopped mushrooms and any optional vegetables. Cook, stirring occasionally, until vegetables are tender, 4 to 5 minutes.
04 -
Stir in water chestnuts, minced garlic, and minced ginger. Sauté until aromatic, about 30 seconds.
05 -
Return the cooked chicken to the skillet and add half of the sliced scallions. Stir to combine.
06 -
Pour the prepared sauce over the mixture. Stir and cook until the sauce is bubbling and warmed through, 30 to 60 seconds.
07 -
Taste and add additional hoisin sauce if desired, according to preference.
08 -
Separate lettuce leaves and arrange on a serving platter. Provide small bowls of sriracha, red pepper flakes, and remaining sliced scallions. Serve chicken filling hot with lettuce leaves and condiments; spoon mixture into lettuce cups, garnish, and consume immediately.