Remove bones and skins from chicken breasts. Halve legs and remove skin too.
Make a marinade with rosemary, juniper berries, parsley, garlic, carrots, celery, yellow beets, onions, 1 tablespoon olive oil and pepper. Add chicken peaces and marinade at least 3 hours, preferably overnight at room temperature.
Remove chicken from the marinade, pat dry, season with salt and sauté in the remaining olive oil on both sides briefly and set aside. Add the drained diced vegetables and roast them with the tomato paste. Pour in the red wine marinade, bring to a boil and skim off the foam while. Add chicken and simmer for about 35 minutes.
Cut spring onions into pieces. Quarter the mushrooms and fry briefly. Add both just before the meat are tender.