Mix flour, salt, and baking powder. Add oil and enough warm water to form a soft dough. Knead 5 minutes, cover, and rest 30 minutes.
Divide into six balls. Roll each thinly and cook on a hot dry skillet for 1 to 2 minutes per side, brushing lightly with oil. Stack under a clean towel.
Cook the Curry:
Season chicken with half the salt. Brown it in oil in batches, then set aside. Cook onion for 7 minutes; add garlic, masala, and cumin and stir for 1 minute.
Return chicken, add the whole pepper and water, cover, and simmer 25 minutes. Add potatoes and cook 20 minutes, then add long beans for 10 minutes until tender. Remove the whole pepper and adjust salt.
Serve each roti with chicken, potatoes, beans, gravy, and boiled egg.
Notes
Keep the Scotch bonnet whole for aroma with controlled heat; discard it before serving.
Warm leftover roti separately in a dry skillet and reheat curry gently for up to three days.