This recipe by James Martin has never failed me.
200g plain flour
Salt and ground pepper
300ml whole milk
4 tbsp vegetable oil
Put 200g plain flour and some seasoning into a large bowl, stir in 3 eggs, one at a time, then slowly whisk in 300ml milk until you have a smooth batter.
Chill in the fridge for at least 30 mins or up to a day.
Heat oven to 220C/180C fan/gas 7. Pour 4 tbsp vegetable oil into the holes of a 12-hole muffin tin, then heat the tin in the oven for 5 mins.
Carefully ladle the batter mix into the tin, then bake for 30 mins until well browned and risen.