700g (1 1/2lb) potatoes, peeled and cut into chunks
Salt and freshly ground black pepper
50g (2oz) unsalted butter
4 tbsp warmed milk
1 tbsp wholegrain mustard
For the gravy:
1 tbsp flour
2 wineglasses red wine
100ml (4floz) beef stock
2 tsp Dijon mustard
Grill the sausages until browned all over, turning regularly. Reserve, keeping warm. In another pan, add the oil and fry onion rings and celery to soften and lightly caramelise. Reserve keeping warm. At the same time, boil potatoes in lightly salted boiling water. Drain and mash with butter and warm milk. Season. Stir in the wholegrain mustard.
For the gravy add flour to the onion pan and stir. Add wine and stock slowly, stirring continuously. Add to onion pan and bring to the boil. Season and stir in the Dijon mustard.
To serve, place onion mix in the base of an individual serving dish. Top with two sausages, then pour over gravy.