In a large bowl, season the beef with 2 tablespoons Jamaican curry powder, 1 teaspoon salt, and 1 teaspoon black pepper. Mix well to coat, then let marinate for at least 30 minutes or overnight for deeper flavor.

Chop the onions, garlic, ginger, and potatoes in advance and store them in the fridge for up to 2 days.

Heat the vegetable oil in a heavy pot or Dutch oven over medium heat. Add 2 tablespoons Jamaican curry powder directly to the hot oil and stir for about 1 minute, until fragrant and slightly darkened. Do not let it scorch.

Add the seasoned beef to the pot and brown it on all sides, stirring occasionally so the meat is well coated in the toasted curry mixture.

Stir in the chopped onion, minced garlic, minced ginger, Scotch bonnet pepper, thyme sprigs, and bay leaves. Cook for 2 to 3 minutes, until the aromatics are fragrant.

Pour in the water or beef stock, adding enough to just cover the beef. Bring to a boil, then reduce the heat to low. Cover and simmer for 1 to 1 1/2 hours, stirring occasionally, until the beef begins to turn tender.

Add the chopped potatoes and a little more water if needed. Continue simmering for 25 to 35 minutes, until the beef is very tender, the potatoes are soft, and the gravy is thick and rich. Season with additional salt to taste.

Remove the Scotch bonnet pepper, thyme stems, and bay leaves if desired. Serve hot with white rice, rice and peas, Jamaican dumplings, or roti.