Preheat an oven to 350 degrees F (175 degrees C).Advertisement
Stir the soy sauce, sugar, 1 teaspoon of black pepper, cornstarch, and 1/2 cup of the reserved pineapple juice together in a saucepan until the sugar is completely dissolved; add the onion, garlic, and ginger. Bring the mixture to a boil and cook until the sauce thickens, about 5 minutes.
Thoroughly rinse the chicken thighs, drumsticks, and wings; pat dry with paper towels. Arrange the chicken in a baking dish; season with salt and pepper.
Bake in the preheated oven for 15 minutes. Pour the pineapple chunks around the chicken pieces; brush the chicken liberally with the sauce and return to the oven for 30 minutes, brushing with sauce every 10 minutes or so.