for 4 servings, for example, with bratwurst sausage, you need
- 2 medium onions, peeled and thinly sliced
- 1tbsp vegetable oil
- A good knob of butter
- 3tsp flour
- 1tsp tomato purée
- 1tsp Dijon mustard
- 100ml red wine
- 250ml beef stock
- Salt and freshly ground black pepper
To make the sauce
- Heat the oil in a thick-bottomed pan and gently cook the onions for 8-10 minutes with a lid on until lightly coloured. You may need to add a splash of water if they are catching on the bottom of the pan.
- Add the butter, flour and tomato purée and stir well over a low heat for a minute.
- Add the mustard, stir well then
- Gradually add the red wine, stirring to avoid lumps forming, before
- Gradually adding the beef stock.
- Season, bring to the boil and simmer gently for 20-25 minutes until the sauce has reduced by about two thirds and thickened. If the sauce is getting too thick, add a little water.
- Remove from the heat and cover with a lid to keep warm.