Peel and coarsely grate potatoes. Toss with salt, then place in a colander over a bowl for 15 minutes to draw out moisture.
Squeeze firmly by hand, then wrap in a clean tea towel and twist to remove as much liquid as possible. Pat dry with paper towels.
Grease a 9in – 23cm high side quiche or tart tin. Press grated potato evenly into base and up the sides, packing firmly. Brush with melted butter or duck fat.
Bake at 200°C – 400°F for about 20 minutes, or until light golden. Check a few minutes early if thin.
Brush crust with beaten egg white and bake 3 minutes more to seal.
Reduce oven to 180°C – 350°F.
In a large bowl, whisk eggs and cream. Stir in Gruyère, feta, capsicum, spinach, olives, sundried tomatoes, oregano, and pepper.
Pour filling into crust. Bake 25–35 minutes, until edges are set and lightly golden, a little jiggle in the centre that isn’t liquid is fine.
Rest 60 minutes before slicing. Serve warm or at room temperature with a fresh salad.
