Place the sliced potatoes into a pan of boiling water and cook for 5 minutes, drain and leave until needed. In a large frying pan add the olive oil and butter and cook the sliced mushrooms until soft, approximately 5 minutes. While the mushrooms are cooking preheat your grill to medium. In a bowl lightly whisk the eggs, cream, parsley and a little seasoning. Pop the potatoes into the pan with the mushrooms, arrange so the pan is evenly covered. Pour in the egg mixture and cook over a very low heat until the egg is setting around the edge, pop under the grill and continue to cook until set.
Serve with fresh crisp salad.