first stab at it:
2 tbsp butter and 2 tbsp avocado oil
fry up an onion in the above mix then add
1/4 tsp salt or more to taste
as much garlic as you think appropriate, fry to remove raw smell
as much ground ginger, ditto
stir in and fry 1 to 2 tsp your favourite sweet curry powder blend
add 1 pint jar base gravy, fry to build flavour
1 can coconut milk, bring to active bubble
add precooked chicken
add a ripe plantain or two, cut into slices OR chopped fresh mango OR a sliced banana OR pineapple chunks
if you want to get it closer to a BIR version add a teaspoon or two of sugar
serve over rice