Scrape the carrots and cut them into large sticks, wash the celery, and cut it into sections.
Cut the chicken into pieces without deboning it and place it in a pot with the veal shank and pork shoulder. Add the vegetables, peeled garlic cloves, bouquet garni, and juniper berries. Season with coarse salt. Cover with beer.
Bring to a boil. Skim off any foam, cover, and let it cook at a low boil for 4 hours.
Remove the meats, discard all the bones and chicken skin. Shred the meats and place them in a large salad bowl or terrine.
Remove the vegetables, garlic, and berries with a skimmer and incorporate them into the shredded meat. Cover with the cooking broth. Let cool, then refrigerate for 3 hours. Serve in slices with a green salad and fries.