Place chicken cubes in a large resalable Ziploc®. Combine the soy or tamari sauce, peanut butter, brown sugar, curry powder and garlic oil and pour over chicken. Shake to coat chicken. Marinate overnight for best flavor.
Thread chicken onto skewers. Heat grill to high. Lightly grease the grill grate and place skewers on grill. Grill for about 12 to 15 minutes, turning frequently until chicken is done.