Toad In The Hole With Roasted-Onion Gravy

Ingredients

6 good-quality pork sausages - about 14oz/400g
1 tbsp groundnut or other flavourless oil (if necessary)
For the batter:
3oz/75g plain flour
1 large egg
3fl oz/75ml semi-skimmed milk
salt and freshly milled black pepper
For the onion gravy:
8oz/225g onions, peeled and sliced
2 tsp groundnut or other flavourless oil
1 level tsp golden caster sugar
2 tsp Worcestershire sauce
1 level tsp mustard powder
15fl oz/425ml vegetable stock made from 1½ level tsp Marigold Swiss vegetable bouillon powder dissolved in 15fl oz/425ml boiling water
2 rounded tsp plain flour
salt and freshly milled black pepper

You will also need a solid-based, flameproof roasting tin with a base of 9×6in/23×15cm, 2 in/5cm deep, and a baking tray 14×10in/35×25.5cm.