1. Cut the stems off the mushrooms, rinse them, and cut them in half.
2. Peel and finely chop the shallot and garlic.
Heat the oil in a pot and sauté the garlic and shallot.
3. Add the rabbit legs and brown them on all sides.
4. Add the mushrooms and stir for 2 minutes.
5. Season with salt and pepper, add the carrots, beer, thyme, bay leaf, and a small glass of water, then bring to a boil.
Reduce the heat, cover, and simmer for about 30 minutes.
6. Meanwhile, cook the tagliatelle in salted boiling water. Drain.
7. Arrange the tagliatelle in a serving dish, add the rabbit and vegetables, and serve immediately.