A great pasta dish for any occasion:
Bring water to a boil with the spiked onion, a tiny bit of vinegar and salt. Put in the cod slices and simmer for twelve minutes. Remove the fish and pull out the bones with a fork. For the sauce, boil the fish stock with the flour butter by half, add the double cream and simmer again. Pour on the crème fraîche and bring to the boil once. Before serving, fold in the cold butter, season heartily with mustard, a splash of tarragon vinegar, dill and salt.
Melt the butter in a saucepan, toss the diced vegetables and well-drained lentils in it. Pour on white wine and chicken stock, gently simmer for ten minutes and thicken the lentils with the cold butter. Season to taste with salt and freshly ground pepper. Serve the fish slices with the sauce, the lentil vegetables with the spinach noodles tossed in butter.