Pre-heat the oven to 200°C/400°F/gas 6.
Peel and finely chop the onion, and using a little olive oil, fry off in a pan on a medium heat. Add the diced carrots and leeks until softened.
Place the mince and peas to the vegetables. Add 300ml of boiling water to your stock cube and add this into the pan, along with a sprinkle of parsley, thyme, salt and pepper.
Leave the mince to bubble away on the hob for about 15-20 minutes, until the liquid has reduced right down and has slightly thickened.
Meanwhile, peel and cube the sweet potatoes and bring to the boil until soft.
Drain the potatoes and mash until smooth. Add a splash of almond milk if needed.
Transfer the mince to an oven-proof dish and assemble the pie, evenly spreading the sweet potato mash on top. Pattern the potato with a fork, then sprinkle with vegan cheese and a crack of black pepper.
Place in your hot oven for around 15-20 minutes, or until piping hot. Enjoy!