Preheat oven to 220C/430F/Gas 8.
Place the flour, eggs and seasoning into a food processor.
Turn on and blend to a paste before adding the milk. Continue to process until a smooth batter is formed.
Pour into a jug and place in the fridge to rest. This works best if you are able to leave it overnight.
Place the Yorkshire tins on a baking tray, then put the beef dripping into the tins and place in the oven. Heat for 5-10 minutes until smoking hot.
Pour the batter into the tins and bake for 10-15 minutes until golden brown and risen around the edges.
Meanwhile, heat a sauté pan until hot then add the butter, sliced onions and garlic and cook for 8-10 minutes until tender but not coloured.
Add the red wine and reduce by half.
Add the beef stock and bring to the boil.
Reduce the heat to a simmer, add the balsamic vinegar and thyme and cook for 10-15 minutes.
Season with salt and black pepper.
Serve poured over the Yorkshire Pudding.
