Have the eels skinned and trimmed by your fishmonger. Cut them into sections of about 5 cm.
Cut the smoked breast into lardons
Heat the oil in a sauté pan, put 50 g of flour on a plate, roll the eel sections in it, quickly enough so that the thickness of the flour remains light.
Immerse the eels in the frying pan, drain them when they are golden.
Brown the onions and bacon for 10 minutes in a casserole dish with 30 g of butter over medium heat.
Add the stemmed and washed mushrooms.
Extend the cooking for 5 minutes.
Put the eels in the container.
Moisten with the beer (reserve 2 spoonfuls) and the veal stock.
Boil for 5 minutes. Add the thyme, the bay leaf and the parsley stalks tied in a bouquet, the peeled and crushed garlic clove.
Season with salt and pepper, add a pinch of grated nutmeg.
Let simmer for 15 minutes. Drain the eels. Keep them warm.
Remove the bouquet from the sauce.
Make the beurre manié:mix 30 g of butter with 10 g of flour. Wet with reserved beer. Stir to avoid lumps.
Pour into the sauce. Allow to thicken while stirring.
Cover the eels. Sprinkle with chopped parsley.
Serve with mash on the side.