lentil shepherds pie

Ingredients250g of dried green and brown lentils, cooked
3 onions, chopped
3 cloves garlic, minced
3 carrots, diced
2 sticks celery, diced
1 leek, chopped
7 lrg white mushrooms, chopped
Lots of peas
1 tbsp mustard
1 tbsp mixed herbs
1 tbsp smoked paprika
1 tbsp tomato purée
1 1/2-2pints of gravy
Salt and black pepper to taste
I just soften all the veggies in a little oil then add in all the other ingredients (except the peas and simmer for 30mins or so. I add in the peas later so they keep there nice vibrant green colour x