In a large pot with a lid, drizzle the oil over medium heat.
Add the onions and cook until starting to soften, then stir in the garlic and whole Scotch bonnet pepper.
Add the chicken pieces and continue to cook, stirring often, until browned on all sides.
Stir in the curry powder, salt, cumin, allspice, black pepper, and nutmeg and continue to cook for another minute, taking care to stir often and not burn the mixture.
Toss in the potato pieces, then pour in the water or chicken stock. Add the thyme leaves and bay leaves.
Bring the mixture to a boil, then cover and cook over medium low heat, stirring occasionally, until the potatoes are tender, 20-30 minutes.
Once the potatoes are fully tender, adjust seasonings to taste, remove from heat, and discard the Scotch bonnet and bay leaves.