Add rice and saffron to boiling salted water and cook for 20 minutes over low heat. Wash the fish, dab dry and cut each fillet into 4 pieces. Drizzle with lemon juice. Melt crab butter in a pot.
Add sherry, wine and crème fraîche and mix. Season with salt and cayenne pepper. Whisk the egg yolks and cream and add to the sauce. Do not let it boil any more! Rinse the crab meat briefly, fold into the sauce and keep warm.
Dab fish a little dry, salt it, turn it in flour and tap it off. Heat the oil in a pan and fry the fish until golden brown. Drain the rice and serve with the fish and sauce. Garnish with chervil.
Zucchini vegetables tossed in butter taste great with it.