Finely dice the onion, celery and garlic and add them to a fry pan over a medium heat with some olive oil. Saute until soft

Thinly chop the carrot, adding this to the fry pan once the onions are cooked 

Add the lentils, diced tomatoes, peas, bay leaves, rosemary and tamari. Bring to a gentle simmer and leave to reduce for roughly 20 minutes 

Prepare the potato mash by peeling and dicing the potatoes, steaming or boiling them until soft 

Take out a mixing bowl, and add in the hot soft potatoes, milk, egg yolks and 1/4 cup of the parmesan. Season with salt and pepper to taste. Mash together well until smooth and creamy 

Once the lentil filling has reduced, pour it into a large baking dish and top with the potato mash and the remaining cheese 

Cook in a preheated oven for roughly 20 minutes, until the cheese on top is golden and crunchy.