Bean stew with meatballs

Name: Bean stew with meatballs
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Cuisine: European
Ingredients: 80 g carrots, cut into pieces; 90 g leek, cut into pieces; 80 g celery, cut into pieces; 30 g butter; 500 g potatoes, diced (1.5 cm); 500 g water; 1 tbsp beef stock paste, homemade or 1 beef stock cube (for 0.5 l); 1 tsp dried savory; 500 g green beans, fresh or frozen (defrosted); 250 g sausage meat, ready seasoned (see tip); 250 g canned butter beans, drained (weight after draining); 1 tsp fine salt; ½ tsp freshly ground black pepper; 2 tbsp fresh parsley, chopped