I made a particularly good toad in the hole last night. There were various factors behind the success, I think.
The batter. It was light, composed half of milk, half of water. Most recipes tell you to add liquid to the flour, stirring to incorporate it before adding more; but this involves working away at the flour, developing the gluten and creating a tougher batter. It is easier to add the flour, tbsp by tbsp, to the liquid, blending with a whisk. The odd lump will do no harm.
The oil. Groundnut is good. Sunflower asserts its flavour, giving you the sense that you're eating something greasy.
The receptacle. Use a roasting tin. The batter will not crisp in a ceramic oven dish. The quantity below formed a thin, crispy batter in a 24 x 33 cm tin.
The sausages. You want good ones, obviously. Some recipes tell you to brown them first; they even use the term "seal". Frying does not seal meat, as experiments have shown; the suggestion that it seals sausages is ridiculous. They will brown in the oven. I lay them on top of the batter, rather than risk splitting them by placing them in the hot oil.
140 ml milk
140 ml water
112 g flour (plain or self-raising)
Beat the egg in a large bowl. Pour in the milk and water, and add a little salt. Gradually whisk in the flour, until you have a batter with the consistency of single cream. The experts advise you to leave the batter to rest for half an hour.
Heat the oven to gas mark 6/200 C. Pour just enough groundnut oil into a roasting tin to coat the bottom, and put the tin into the hot oven for 10 minutes. You want it to be hot, so that the batter will start crisping.
Check the consistency of the batter, adding a little more milk or water if it seems thick. Take the tin out of the oven and pour in the batter, tilting the tin to spread it over the surface. Lay the sausages on top.
Bake for 30 to 35 minutes, or until set and crisp.