Toad in the hole with onion gravy

We're having English dinner tonight. That's the first time I made it, and noone was dissapointed!

For the dish:

8 small sausages for frying
2 onions, cut into wedges
olive oil
2 eggs
150g flour
300ml milk
2 t.s. mustard powder

Oven 180C.
First in the oven proof dish with little olive oil bake sausages and onion for about 20 minutes. Mix flour, mustard powder, milk, eggs, season to taste and pour it over sausages. Put back into the oven for another half an hour or so.

For the gravy:

2 small onions, thinly sliced
2tb.s butter
2tb.s. oil

Cook in a sauce pan for 8-10 minutes. Now add:

half a t.s. sugar
1t.s. balsamic venigar
apr.500ml beef stock
pepper to taste

Cook for another 5 minutes and add mixture of:

3 full t.s. corn starch
little water

Cook for a couple of minutes, until thickens. Keep warm until serving with the main dish.