Potato Quiche

It sounds boring. It sounds plain. It's nothing short of surprisingly delicious! So few ingredients, and so simple, yet it makes a lovely, surprisingly light quiche.

1 blind baked pie crust, completely cooled
2 Tbsps (1oz/28gr) butter (or ham fat for a bit of a smoked flavor)
8 to 10 oz potatoes, skin-on, grated
1 bunch chives, chopped fine (about 1 oz or 40 to 50 grams)
8 oz sharp cheddar cheese, grated (optional, substitute 1.5 oz of the cheddar for parmesan for an added kick)
3 large eggs
½ cup heavy cream
½ cup milk
1 tsp Dijon mustard

1. Blind bake the pie crust if it isn't already.
2. Pre-heat the oven to 375°F.
3. In a non-stick pan melt the butter and fry the grated potato over medium heat until just al dente. VARIATIONS - you can gently cook the potato and avoid browning it which will make for a very light quiche, OR cook the potato at a higher temperature to whichever degree of browning you want for a deeper flavour, a little like hash-browns.
4. Add the chives and turn off the heat, only slightly cooking the chives. Set aside.
5. In a bowl, whisk the eggs then add the cream, milk and mustards. Mix well.
6. Put the potato at the bottom of the crust. Make sure the potato is in small pieces so that the custard can seep into it; it may have glommed together into masses while pre-cooking. 
7. Following the potato is a layer of the grated cheese, and finally pour the egg mixture over all.
8. Bake in the oven for 40 to 50 minutes, or until the center is set, the custard is puffed up and browned.