Trim the chicken and cut into 2" pieces. In a large bowl, combine the chicken and corn starch. Toss until all the chicken is coated. Add extra corn starch if need to make sure all chicken is coated.

In a saucepan or microwave safe bowl combine the soy sauce, water, brown sugar, garlic, and ginger. Heat until all the sugar is dissolved.

Preheat griddle to medium high heat.

Add the oil to the griddle.

Add the chicken to the griddle and cook until it's crispy on the outside.

Add the sauce and half the sliced green onions to the chicken and let the sauce thicken for about 1 minute.

Remove the chicken from the heat. Serve in individual lettuce leaves and garnish with sliced green onions.