Place the first five ingredients in a small pot and whisk to combine. Add the pineapple and its juice. Boil 1 minute, or until thickened. Cover and remove from the heat.
Place an oven rack 6" beneath the broiler and set the broiler to high. Place chicken on non-stick baking sheet, season with pepper. Broil 3 to 4 minutes per side, or until nicely browned.
Reduce the oven heat to 375 degrees F. Set the chicken, skin side up, in a 9"x13" baking dish and spoon over the sauce. Cover and bake for 30 minutes then uncover and bake 10 minutes more, or until cooked through. Plate the chicken, top with sauce, sprinkle with green onion and serve.