Cut 500 g meat sausage into pieces (preferably strips).
Peel almost 300 g onions and cut into eighths. Fry both in butter / margarine until light brown, then remove. Put 40 g flour in the fat and let it sweat until it is lightly browned. Deglaze with 3/8 liter of warm water and 1/8 liter of milk, stirring constantly, and bring to the boil. Stir in 4 level tablespoons of mustard. Season the sauce with salt, pepper and a little sugar. Add the sausage and onion strips and heat them up. Serve sprinkled with chives and baguette.