Heat the oil in a medium saucepan over medium heat until shimmering. Add the onions, garlic, and ginger and cook, stirring, until the mixture begins to soften and the onions are almost translucent, 5 to 8 minutes. Add peppers and cook, stirring, for another 2 minutes. Add curry powder, stir, and continue to cook until curry powder turns deep gold and is fragrant, about 1 minute. Season the chicken with salt and pepper, add to pan and continue to cook for 8 to 10 minutes. Add the potatoes and cook for 3 minutes before adding the chicken broth, coconut milk, Worcestershire, vinegar and hot sauce. Reduce heat to low and simmer until chicken is cooked, potatoes are tender, and sauce is lightly reduced, about 30 minutes. Season to taste with salt and pepper. Garnish with cilantro if desired, and serve with sides such as grilled or fried plantains, beans, and rice.