Preheat the oven to 180°C.
Score the skin of each fish fillet at 2cm intervals and insert a mint leaf into each cut.
Heat an ovenproof frying pan with oil, clarified butter, and a garlic clove.
Season the fish and cook skin-side down in the pan for 4 minutes.
Turn the fillets and finish cooking in the oven for 4 minutes.
Remove from oven, discard garlic, and drizzle with lemon juice.
Boil the chopped potatoes and 5 cloves of garlic in salted water for 20 minutes.
Drain potatoes and mash them with heated cream, butter, nutmeg, and seasoning.
Blanch the broad beans and peas in boiling salted water, then refresh in ice water.
Peel the beans and set aside with the peas.
Simmer 150ml of cooking water with garlic and shallots for 5 minutes.
Add the beans, peas, cream, and chopped mint to the pan and warm through.
Serve the fish over a dollop of mash with the fricassée and sea salt.