Finger-Licking Curried Chicken

1 1/2 tsp curry powder
1 tsp thyme, crushed
1 stalk scallion, chopped
1 Tbsp hot pepper, chopped
1 tsp black pepper, ground
8 cloves garlic, crushed
1 Tbsp ginger, grated
3/4 tsp salt
8 pieces chicken, skinless (breast and drumstick)
1 Tbsp olive oil
1 C water
1 medium white potato, diced
1 large onion, chopped