Add a little water to your pan and cook the onions and carrots for about five minutes until they're soft. Add the lentils, curry paste, tomatoes, tomato puree and 300ml/half a pint of water. Cover then simmer for 25 minutes until tender. Remember to keep checking it to make sure it hasn't caught on.
While this is cooking away it's time to make the mash! Cooks the parsnips in boiling water for 10 minutes then add the leeks for the last two minutes until they're all tender. Drain then season and mash away.
Once the lentil mixture is cooked, put into a flame proof dish like a Pyrex dish and then put the mash on top. Put it into the over and grill under golden.