1. Preheat the oven to 180°C.
2. Take a 12-hole standard muffin tin and line each hole with one slice of Parma ham covering the base and sides.
3. Heat the oil and sauté the onion for 4 minutes until soft and place aside to cool.
4. Mix with the tomatoes, blue cheese, olives and chives. Divide into the prepared bases.
5. In a jug, whisk the eggs and milk together and add a pinch of black pepper.
6. Pour equal amounts into the prepared mixture and sprinkle with the Parmesan.
7. Bake in the oven for 15 minutes or until puffed up and set.
8. Cool for a few minutes and gently remove from the muffin tin.