Lentil, kale and sausage soup

2 kielbasa or similar cooked sausage, sliced
1 bunch fresh kale, thinly sliced
1 onion, chopped
2 garlic cloves, sliced
1/2 cup green lentils
3 cups chicken broth
1 tablespoon balsamic vinegar

Cook onions and garlic in olive oil. Add broth and lentils, boil until soft. Add kale and sausage, simmer for 15 minutes. Stir in vinegar, salt and pepper to taste.

Served with fresh sliced apples.