Cut the mushrooms into slices. Heat half the butter in a shallow pan and sauté the mushrooms for 1 minute over medium heat. Add the shallot and sauté for another 1 minute, being careful not to discolour the shallot.

Place in a sieve and drain the cooking liquid.

Return to the pan, deglaze with the wine and reduce by half over medium heat. Add the veal stock or gravy and simmer gently for 15-20 minutes, until the sauce is thick enough to stick to a spoon.

Remove the pan from the heat and whisk in the remaining butter and spices. Check the taste and add salt and pepper if needed.