Preheat oven temperature to 350°F.
In a large sauté pan, melt the butter over medium-high heat until it turns golden. Add the leeks and sauté until wilted but still bright green, about 2 minutes.
Season with salt and pepper and transfer to a bowl to cool.
Sautee the diced smoked ham for 3-5 minutes until slightly browned. Add to the leek mixture.
In a large bowl, whisk together the eggs and cream. Season with the 1/2 tsp. salt, 1 or 2 grindings of pepper.
Scatter the leek mixture evenly over the bottom of the pastry shell. Pour in the egg mixture and mix lightly with a fork to distribute evenly. Sprinkle evenly with the cheese.
Bake until the custard is set and the top is golden, 40 to 45 minutes. If the custard is set but the top has not turned golden brown, slip the quiche under the broiler for 1 to 2 minutes, watching closely. Let cool about 20 minutes in the pan on a rack before serving. Makes one 9-inch quiche.