1. Preheat your oven to 200C/400F/Gas 6.
2. Pop the sausages in a roasting tin and into the oven, after 15 minutes add the onions to the tray and turn the sausages over, pop the tray back in the oven and cook it for 10-15 minutes more until the sausages are lovely and brown and the onions are golden.
3. Meanwhile, to make your mash, boil the potatoes in plenty of boiling water until they're nice and tender.
4. Drain them and mash them up with the butter and milk until they're nice and smooth with no lumps.
5. Whisk the gravy granules with 200ml boiling water and the mustard, if you fancy it.
6. Serve the sausages, roasted onions on top of the mash and top with your lovely, steamy gravy.
7. Make sure your dinner is fully cooked and piping hot before serving it up.
Recipe courtesy of The co-operative food