Peel and finely dice the shallots. Wash the rosemary, pluck the needles roughly from the twigs. Wash the rabbit pieces, dab dry and season with salt and pepper. Melt butter in a large pot and fry meat in it.
Take out the rabbits. Deglaze the roast with cognac and flambé.
Pour wine and 100 ml water into the pot, put rabbit back in. Add rosemary and shallots. Season with salt and pepper and simmer covered for about 45 minutes at low heat.
Add both mustards and crème fraîche. Bring to the boil, simmer for about 5 minutes, season with salt and pepper.