Serves 4 as a starter or 2 as a main course
Preheat the oven to 220°C/fan 200°C/gas 7.
Roast the garlic for 30 minutes, or until the flesh is very soft and beginning to colour golden brown. Allow to cool a bit, then skin all the garlic cloves, leaving just the soft roasted flesh.
Melt the butter in a small frying pan and, when it is hot but not smoking, throw in the curry leaves and cardamom. The curry leaves should spit and pop. Fry, stirring constantly, for a good 30 seconds or so.
Add all the garlic flesh and the turmeric and mash it into the butter.
Allow to sauté gently for a further 2 minutes or so while you add the chilli flakes (if using) and sea salt to taste. Be careful not to let the garlic burn. If the butter has gone a faint nut brown, this is fine. When the butter is done, leave to one side.
Put a small frying pan over a high heat and get it very hot. Pour a little sunflower or vegetable oil on a plate and dip both flat sides of each scallop before lowering them into the pan. (This should be done to the coral too, if using.) An aggressive sizzling should be heard the minute the scallops kiss the pan. This hard fry will caramelize the plentiful sugars in the scallop meat, creating that heavenly savoury toffee.
Turn the scallops (and corals, if using) after about 1–1½ minutes, or after one side is browned, and brown the other side for a further minute. The middle of the scallop should remain almost raw. Warm the curried garlic butter now, if need be.
Season the scallops with a little extra sea salt and arrange them either back in their shells or on a plate.
Spoon over the warmed garlic butter and serve with wedges of lime, if desired.