Peel and cut potatoes into thick slices and parboil in salted water for about 8 minutes. Drain and set aside.
Fry pork sausages until nicely brown all over, then cut into thick diagonal slices and place in a casserole dish.
In the same pan, fry a couple of sliced red onions until softened, then add a Tbs plain flour. Mix well and cook
for a minute or two, then add a cup of chicken stock, stirring well until you have a smooth thickish sauce.
Stir in a good Tbs grain mustard, season with a grinding of black pepper and pour over the sausages. Cover
the sausages with the potato slices, season well with more freshly ground black pepper, dot with knobs of butter
and bake in a 190°C oven for 30 minutes, until the top is golden and crispy. Serve with a green veg.