Savory Wild Goose Stew

• 8 onions
• 6 potatoes (peeled)
• 5 carrots quartered
• 4 celery stalks (chopped)
• 3 geese boned
• 2 bay leaves
• 525 gr green beans (frozen)
• 120 ml oil
• 80 gr mushrooms (fresh sliced)
• 65 gr flour