1. Place the slices potatoes into a pan and cover with some water, add a pinch of salt and bring to the boil.
2. Allow to boil for 2 – 3 minutes then remove from the heat and drain.
3. Heat the oil in a large oven proof pan, then add the onions and garlic, cook until the onions have caramelised then remove from the pan.
4. Add the butter to pan and melt over a low heat, then add 1/3 of the potatoes, and season with some salt and pepper.
5. Spread half the onion and garlic mixture over the potoates and add a sprinkling of parsley.
6. Add another layer of pototoes (half of what is remaining), then spread over the remaining onion and parsley.
7. Season with some salt and pepper and place in a preheated oven and bake at 200C/400F for 12 – 15 minutes.