If using fresh snails, they must be starved for days, then rinsed several times in salted, then vinegared water before being boiled in cold water - today it is easier to buy prepared (canned or frozen) snails, which skips this step.
Cook the snails with the bay leaf, thyme and rosemary for about 30 minutes so they take on the aromas, then drain.
In a pan, brown the snails in hot olive oil with the whole garlic cloves and one bay leaf from the cooking water.
Cut up the rabbit, season with salt and pepper, and brown it in olive oil in a pot. Pour over the brandy and carefully flambé it.
Pour in the beef stock and cook over low heat until the meat is tender.
In a mortar, crush the roasted hazelnuts with the chocolate, thin with a little stock, and add to the rabbit.
In another pan, sauté the onion, add the tomato sauce, and when it thickens, add it to the rabbit together with the snails.
Simmer everything together over low heat for a few more minutes before serving.