Meanwhile, using a mincer (either hand cranked or a mixer attachment) process the leftover roast lamb meat straight into the casserole dish you will be cooking the dish in.
Peel and quarter the onion and feed this through the mincer along with the carrot/s at the same time as the meat.
Once all meat, onions & carrots minced into the casserole dish, add Worcestershire sauce, tomato sauce, salt, pepper and frozen peas. Mix well.
You can add in extra sauce/liquid here if you feel the mix is too dry. This could be more of each of the sauces, some beef broth, brown gravy or just water. Whichever taste you would prefer.
Once the potatoes, sweet potatoes & pumpkin have fully cooked, drain and mash them with butter, milk & pepper until smooth and all lumps are gone.
Spoon the mash on top of the meat mixture and spread out evenly.
I like to leave the top of the mash rough to create peaks that will get a little darker and crustier when baking.
Sprinkle the top with paprika or grated cheese & then place in the oven for 30-40 minutes.
Once bubbling, remove from the oven & serve.
We generally serve it on its own in a bowl, but you can serve with steamed greens on the side.