Preheat the oven to 180 C, 160 Fan, Gas 4. Grease a 12 hole muffin tin.
PLace the flour, baking powder, salt, pepper, mustard seeds and half the cheese in a large mixing bowl.
Mix the eggs, milk, mustard, onion, garlic, parsley and half the pickle together. Add to the dry ingredients and mix lightly until just combined.
Mix the remaining pickle and remaining cheese together separately. Half fill each mould in the muffin tin with the flour mixture, then place one twelth of the cheese and pickle mixture on top of each one. Top with the remaining muffin mixture.
Sprinkle with the sesame seeds and bake for 15-20 minutes or until a skewer inserted comes out clean. Remove from the oven and allow to cool in the tin.