Clean the carp of scales and cut it into rings, salt and set it aside. Peel the onions and carrots and cut into round slices, grate the lemon rind. Put everything at the bottom of the pot. On it, add the pieces of carp, add cloves and bay leaves, and 3/4 of the beer.
Cover the dish and simmer over low heat for about 20 minutes. Braise the flour in the butter until brown and add the remaining beer. Add the vinegar and pour it over the carp. Once ready, take the carp out from the dish and keep warm.
Strain the sauce through a sieve. Sweeten slightly. The sauce needs to come to a boil again, pour it over the carp pieces. Portions of the sauce are served separately.