Wash fish with lime juice, rinse thoroughly, and pat dry. Marinate with green seasoning, salt, half the pepper, and curry powder for 1 hour.
Lightly dust the marinated fish with flour.
Heat oil over medium-high heat and fry fish 4 minutes per side until golden. Drain on paper towels.
Discard oil and wipe pan dry. Add the reserved marinade water, setting aside any residual oil.
Heat 2 tablespoons of vegetable oil; sauté the onion and garlic on low heat until softened.
Add scotch bonnet, tomato, remaining pepper, and 2 tablespoons of curry powder; cook 3–4 minutes until fragrant.
Stir in green mango, then add reserved marinade liquid; bring to a boil. Cover and simmer 6–8 minutes until mango is tender.
Gently add fried fish and scallions, simmering 5 minutes to combine flavors.
Taste and adjust salt and pepper if needed. Serve hot with rice or roti.
