This veg-packed shepherd's pie is loaded with delicious flavours and is the perfect comfort food for a dreary day. Easy and cheap to make. Gluten and dairy free. Low carb, paleo.
In a large frying pan, heat the oil and fry the onion, carrot and celery gently over low-medium heat for about 5 minutes, until the veg is softened and the onion translucent. Add the mince and fry for another 10 minutes until the meat is browned and the veg soft. Stir through the mustard powder for the last 3 minutes. Pour in the chopped tomatoes then refill the can to the top with water (or stock) and pour in, too. Stir through the Worcestershire sauce and herbs, then bring to the boil and allow to simmer for 20 minutes, or until thickened and the flavours have intensified. Add the spinach for the last minute to wilt, then pour the sauce into a large casserole dish and set aside.
While the sauce is thickening, preheat the oven to 200C/400F/gas 6, and bring a large pot of water to the boil. Add the diced parsnips or celeriac and potatoes and boil until soft (about 20-25 minutes). Mash with a potato masher or blitz in a food processor with the olive oil and milk. Season to taste, then spoon over the meat sauce in the casserole dish. Scatter over the cheese, if using, then bake in the preheated oven for about 15-20 minutes, until the sauce is bubbling up round the sides and the mash has darkened slightly (if using cheese, it will go a lot more golden - without, it can be quite pale still).