Heat the butter in a pan. Add the onion and mushroom. Cook over medium heat stirring occasionally until the onion is translucent. Add the chopped ham and cook for another 5 minutes. Remove from heat and let cool down.

Preheat oven to 350°F

Crack all the eggs into a mid size bowl. Whisk the eggs, then stir in the cream. Add to that the pinch of salt and pepper.

Spoon the cooled ham mixture into the prepared pie shell. Sprinkle the grated cheese over top the ham mixture. Pour the egg and cream mixture over top.

Cook in the middle oven rack at 350°F for 50 - 55 minutes. Remove from oven and let cool 10 minutes before cutting into quiche.