Fry shallots in butter gently before adding clams, garlic, and cider.
Steam clams until open, سپس strain through a colander while reserving the cooking liquid.
Portion the brill into 140g skinless fillets.
Blanch peas in salted boiling water for 2 minutes and refresh in cold water.
Season fish and fry slowly in oil over low heat until golden-brown.
Fry shallots and mushrooms in butter without coloring them.
Add reserved clam liquid to the mushrooms and reduce by half.
Stir in cream and crème fraîche, bring to a boil, then lower the heat.
Turn the fish over to finish cooking.
Add peas and clams to the sauce to warm through.
Sauté kale and courgettes in 50ml water and butter for 2 minutes.
Plate the fish and vegetables, finish sauce with tarragon, and garnish.