Rainbow cabbage rolls with mushroom sauce

Name: Rainbow cabbage rolls with mushroom sauce
Prep time: 30 min
Cook time: 2 h 40 min
Total time: 2 h 40 min
Yield: 6 portions
Ingredients: 12 cabbage leaves; 1000 g water; 500 g potatoes; 300 g dried red lentils; 3 sprigs fresh dill; 200 g feta cheese; 2 onions; 30 g extra virgin olive oil; 1 tsp sea salt; ½ tsp ground black pepper; 300 g liquid vegetable stock; 20 g dried porcini mushrooms; 150 g boiling water; 1 tbsp cornflour; 1 tbsp water; 1 onion; 20 g unsalted butter; 200 g button mushrooms; 50 g white wine; 300 g pouring (whipping) cream; 2 - 3 tsp Vegetable stock paste; ¼ tsp ground black pepper; 10 g lemon juice; 1 sprig fresh dill