Set the freshly grated potato in a colander over a bowl. Squeeze out the excess water. Beat in the egg, salt and grated onion.
Pat into a well-oiled stoneware pie plate, building up the sides of the crust with your fingers. Place into oven and set temperature to 400° F (never place pottery into a preheated oven). Bake 30 minutes, then brush on a little oil for a crispier crust. Bake 15 more minutes.
Meanwhile, saute the onions and garlic in butter for 5 minutes. Add herbs, cauliflower and cook 10 minutes, stirring occasionally. Season to taste with salt and the pepper.
Spread half the cheese into the baked crust (okay if it’s still hot). Top with the cauliflower mixture, then the rest of the cheese. Beat together the egg and milk and carefully pour over. Dust liberally with paprika.
Lower the oven temperature to 375° F and bake for 35-40 minutes, until pie is set and browned.