Preheat the oven to 200c.
Peel and dice the onions, carrots and sweet potato and place them in the casserole dish along with the tinned tomatoes. Stir regularly and bring to the boil.
Add the minced beef and all of the other ingredients apart from your OXO cube.
Stir well for 5 minutes or until the mince is about 30% cooked.
Crumble the OXO cube into the casserole dish and also pour in 250ml of boiling water.
Mix well and place the lid on your casserole dish.
Place it in the oven and cook for a further 30 minutes.
Stir and serve.