Sift the flour, salt and baking powder into a mixing bowl.
Add the bacon and cheese and fold in with the mustard , herbs and cayenne. .
Mix together the eggs, yogurt and oil or butter and fold into the mixture with the lightest of touch, until just blended.
Spoon the mixture into the muffin tins. Sprinkle with some extra cheese.
Bake in a preheated oven, 180C / gas mark 4 for 20-25 minutes until golden and firm. Remove and allow to cool in the tin for 10 minutes.