Preheat oven to 375 degrees F
Place the shredded potato, grated onion and salt in a mesh colander over a bowl or in the sink. Let sit 10 minutes.
Meanwhile, generously oil (with a brush or by spray) a 9-inch glass pie pan (so the potato crust won’t stick). Once the mixture has been allowed to sit, squeeze out as much liquid as you can (you can do by hand and then by kitchen towel – this process helps make the crust crusty.
In a medium bowl, combine the potato/onion mixture with the egg white. Spread the mixture in the prepared pie pan and press it evenly into place, on the bottom and up the sides of the pan. (Make sure the side top edge is even –thickness, reducing the chance for individual potato shreds to burn.)
Place the crust in the oven and bake for 20 minutes. Brush the crust with the olive oil and return to the oven for another 15 to 25 minutes, until golden. Remove from the oven while you finish the filling.
In a large sauté pan heat the olive oil and butter over medium heat. Sauté the onions, garlic and salt and pepper for a few minutes.
Add the diced red bell pepper and continue to cook and soften the vegetables, another 3-4 minutes. Stir in the dried thyme and basil. Carefully mix in the cauliflower florets. Add the water or broth, cover, and cook, stirring occasionally until the cauliflower is tender, about 9 to 12 minutes.
Meanwhile, whisk the eggs and milk together and set aside.
When the cauliflower is tender, add the greens, re-cover the pan and turn off the heat, allowing the greens to wilt for a few minutes. Gently stir in the greens to evenly distribute in the mixture.
Spread half of the shredded cheese over the bottom of the potato crust.
Spoon the cauliflower mixture over the cheese and top with the remaining cheese.
Evenly pour the egg/milk mixture over the filling and dust with the pie with paprika.
Put the pie back into the oven, and bake until the egg mixture is set, about 35 to 40 minutes. This can be served hot or warm.