Porcini & Puy Lentil Lasagne

Name: Porcini & Puy Lentil Lasagne
Cuisine: European, Italian, Mediterranean
Ingredients: 1 x 30g pack Merchant Gourmet Porcini Mushrooms; 1 onion, finely chopped; 2 garlic cloves, crushed; 300g button mushrooms, chopped; 2 carrots, diced; 2 celery sticks, finely chopped; 1 tbsp tomato purée; 200ml red wine; 1 x 400g tin chopped tomatoes; 200ml vegetable stock; 1 tsp yeast extract; Pinch caster sugar; 2 packs Merchant Gourmet Simply Cooked Puy Lentils; Sprigs of thyme and rosemary; 2 bay leaves; Salt and black pepper; 75g plant-based butter; 75g plain flour; 700ml non-dairy milk; 1 tbsp Dijon mustard; 3 heaped tbsp nutritional yeast; Pinch grated nutmeg; Freshly ground black pepper; Lasagne sheets; Vegan cheese alternative, grated (optional)