Chicken and veggie lettuce cups

Ingredients

• 1 1/4 pounds boneless, skinless chicken breast or thigh
• 1 tablespoon soy sauce
• 1 tablespoon dry sherry (or white wine, or sake, or skip it)
• 1 clove garlic, minced
• 1 small onion, cut into 1/4″ dice (about 1/2 cup)
• 1 large or 2 small stalks celery, cut into 1/4″ dice (about 2/3 cup)
• 1 medium carrot, cut into 1/4″ dice (about 1/2 cup)
• 2 medium zucchini, cut into 1/4″ dice (about 2 cups)
• 3 tablespoons cooking oil
• 2 teaspoons ginger, minced
• 4 tablespoons hoisin sauce
• 4 tablespoons soy sauce
• 2 tablespoons white or rice vinegar
• 1 teaspoon sugar
• 1/2 teaspoon salt
• 2 teaspoons cornstarch
• 1/2 teaspoon sesame oil
• Crushed red pepper or sriracha sauce, to taste
• Butter lettuce or iceberg leaves, rinsed and dried
• Chopped cilantro or peanuts, for garnish (optional)