Season the chicken with salt and pepper to taste. Place the cornstarch in a shallow bowl.
Coat both sides of each piece of chicken in cornstarch, shaking off the excess, then set them aside in a single layer on a sheet of foil or other work surface.
In a 12-inch skillet over MEDIUM-HIGH, heat the oil. Add the chicken and cook for 4 to 5 minutes, per side, or until golden brown and cooked through. Transfer to a plate lined with paper towels and set aside.
In the same skillet over LOW heat, melt the butter. Add the garlic and ginger and saute for a minute or two, until fragrant. Add the soy sauce and brown sugar and cook, stirring, until it thickens slightly to a glaze-like consistency. Return the chicken to the skillet and spoon the glaze over the top. Remove from the heat and garnish with green onions.
Slice and serve over cooked rice.
