olive oil
1 large onion, chopped
2 diced carrots
2 diced sticks celery
2 cloves garlic, crushed
1/2 tsp dried chilli flakes 
200g diced chestnut mushrooms
300g puy lentils
1 tin chopped tomatoes
3 tbs tomato puree
1tsp dried oregano
2 bay leaves
1l veg stock

Heat 2 tbs oil in large pan and add onion, carrots, celery, garlic and dried chilli. Cook 10 mins until softened. Add mushrooms and cook for 5 mins until softened. Stir in the lentils, copped tomatoes, tomato puree, herbs and stock. Bring to a simmer, then cook 25-30 mins until lentils are tender but not mushy and the sauce is thickened.