Cooking minced/ground beef with a jar of sauce
Fry the mince in a saucepan big enough to hold the sauce until it's brown all over, add the sauce and simmer for an hour or two.

Mince is usually made from cheap cuts of meat. This means, while it will technically be cooked after a few minutes, it will also be tough and chewy. Browning it in the pan then simmering it slowly in the sauce will result in nice tender, tasty mince.

Incidentally, 1kg of meat is a lot for one person, so be prepared to portion it out into freezer bags or tubs. All you have to do then is defrost it overnight in the fridge then reheat in the pan for a quick meal. 

You might also consider bulking it up a little with some diced onions and carrots; there might be some in the sauce jar but they will be mush. Fry them in the pan for 10 minutes on a medium heat before adding the mince and proceeding as above.