Soak mushrooms in ¾ cup (175 mL) water until soft, about 30 minutes. Drain, reserving ½ cup (125 mL) of the soaking liquid; dice mushrooms. Cut chicken into ½-inch (1 cm) dice; mix with ¼ tsp (1 mL) each salt and pepper.

In nonstick skillet, heat 2 tsp (10 mL) oil over high heat; add green onions and fry for 10 seconds. Add chicken and sauté until no longer pink outside, about 2 minutes; transfer to bowl.

Add 1 tsp (5 mL) oil to pan; add mushrooms and carrots. Sauté until lightly browned, about 3 minutes; stir in mushroom soaking liquid and oyster sauce.

Add chicken mixture; cook until sauce is thickened, 1 to 2 minutes. Stir in 1 tsp (5 mL) oil; remove from heat. Serve with lettuce leaves to wrap around spoonfuls of chicken mixture.