Wash chicken with vinegar or lime juice and water, then pat dry.
In a large bowl, season chicken with curry powder, all-purpose seasoning, salt, black pepper, garlic powder, and paprika. Mix well to coat. Let marinate at least 1 hour, preferably overnight.
Heat vegetable oil in a large pot or Dutch oven over medium heat. Add 1 teaspoon curry powder to the oil and 'burn' it for 1 minute, stirring constantly (this deepens the flavor).
Add chicken pieces to the pot and sear until browned on all sides, about 5–6 minutes.
Stir in onion, garlic, thyme, scallions, ginger, and pimento. Cook for 2–3 minutes until fragrant.
Pour in chicken broth (or water) until chicken is just covered. Bring to a boil, then reduce to a simmer.
Add Scotch bonnet pepper (leave whole for mild heat, chop for extra spicy) and diced potatoes. Cover and simmer 35–45 minutes, stirring occasionally, until chicken is cooked through and potatoes are tender. Add more liquid if needed.
Adjust seasoning to taste and remove Scotch bonnet if left whole.
Serve hot with white rice, rice and peas, or roti.