In a large bowl combine chicken, curry powder, allspice, dried thyme, all purpose seasoning, ground ginger, salt, black pepper, onion and garlic. Mix together and let marinate for 20 minutes or overnight in the fridge.
In a dutch oven, heat olive oil over medium-high heat. Add 1 1/2 tablespoons of curry powder and burn the curry. "Burning the curry" is not cooking the curry until it burns as the saying implies. It is blooming the curry to release the flavors as you would if you were toasting different spices. You want to do this for about 30 seconds stirring with a wooden spoon.
Take the chicken and all the marinade and add it to the pot and cook for about 10 minutes stirring occasionally.
Add a cup of water and potatoes to the pot and give a good stir then bring to a boil. Lower heat to medium heat and cover cooking for 20 minutes.
Remove lid and cook uncovered for about 5 minutes to reduce and thicken the gravy.
Serve nice and hot with white rice!