Preheat oven to 180 C or Gas Mark 7.
Mix all the ingredients together in a large jug or bowl. Prepare Yorkshire Tins by lightly greasing with olive oil. (I use muffin tins instead and these work out fine) and place the tin in the oven to heat up for a few minutes. Pour the batter into the hot tins to just about ½ way up. If you are using the mixed seeds, sprinkle these on the batter. Don't worry if they sink to the bottom, they will find their way to the top once the Yorkshires start to rise in the oven.
Bake for 25- 30 minutes until well risen and they release easily from the tin.
Makes 12 Yorkshire Puddings.
Tip: For truly spectacular Yorkshires try placing a baking tin filled with boiling water underneath the puddings while they are in the oven. The steam from the water helps to give them the most magnificent rise and also creates a crispy outer crust.
This batter also makes great Toad in the Hole