Season the lamb on all sides with salt and pepper. In a Dutch oven on medium-high heat add the olive oil. When the oil begins to swirl, add the shanks and sear until golden on all sides. Remove the shanks to a plate and add the butter, curry powder, allspice, and paprika. Stir with a wooden spoon until fragrant and the spices darken, about 2 minutes.
Add the onions, bell pepper, garlic, thyme, scotch bonnet, and then season with salt and pepper. Allow the vegetables to become tender and golden with the spices, about 5 minutes. Stir everything together then add the shanks back to the pot. Add the chicken stock, cover and bring to a simmer.
Simmer, stirring occasionally, until the lamb is fork tender, about 2 hours. Taste and season if needed, then add the potatoes and simmer until the potatoes are fork tender, about 30 minutes more. If making the day before, refrigerate and remove the film of fat from the top before reheating.
Serve the lamb shanks over Right Rice, recipe follows and garnish with chopped cilantro.
Rinse the rice 3 times to remove the starch. Put the rice in a medium saucepan and fill with enough water to cover the rice by 1/2-inch or measure by placing your thumb tip on the rice and filling the pot with water until the water reaches the middle of your thumbnail. Bring the rice to a simmer, cover and cook until tender and the liquid is evaporated, about 15 minutes. Remove from the heat and let the rice stand another 5 minutes, covered.