Pre-heat oven to gas mark 6/200°C/180°C fan.
Place potatoes in microwave and cook on full power for 4 minutes, then remove and allow to cool.
Heat oil in a large saucepan over a medium-high heat. Add butternut, pumpkin, onions, carrots, mushrooms, celery, parsnips, garlic, Worcester Sauce, mixed herbs and tomato puree and sauté for 5 minutes, until vegetables begin to brown.
Then add in tinned tomatoes, and vegetable stock and stir.
Let mixture simmer without boiling until sauce has reduced down.
Place the mixture into a small oven proof dish.
Thinly slice the cold potato and place on the top vegetable stew.
Bake in oven for 40 minutes, until golden brown.
Make in bulk by doubling ingredients list to make 2 serves. Just remember to divide potato evenly between serves to get the right protein per serve.