Soak the cashews in cold water for 30 minutes.
Cook the brown rice according the packet instructions. Drain and set aside.
Pre-heat the oven to 180°C (fan)/200°C/gas mark 6. Grease a 1kg loaf tin and line with baking paper
Peel and chop your parsnips and steam (or boil) them until soft. Drain and set aside.
While the parsnips are cooking grind your chia or flax seeds to a powder in a spice grinder or food processor. Add the 6 tbsp water and stir until you have a gloopy paste that's a bit like glue. Set aside.
Heat your olive oil in a frying pan and sauté the onions and leeks until soft, stirring often. Add the garlic, nutmeg, allspice, dried sage, miso paste and nutritional yeast and continue cooking for a moment or two. Turn off the heat and set aside.
Drain the cashew nuts and roughly chop. You can do this in a food processor but don’t over do it. You want chopped nuts rather than ground.
Put the cashews in a large mixing bowl and add the onion mixture along with your flax eggs, the cooked parsnips, the cooked rice and the chopped parsley. Roughly mash until well combined but still with plenty of texture.
Season with salt and pepper to taste.
Transfer to your prepared tin and bake for 30 minutes. Cover with foil and return to the oven for a further 30 minutes.
Allow to cool in the tin for five minutes then turn out and serve immediately. If it gets stuck in the tin run a sharp knife around the outside of the nut roast to loosen it.
Serve with roast potatoes, veggies and a vegan onion gravy.