2 pounds small red potatoes, sliced 1/8- to 1/4-inch thick on a mandoline
1 large red bell pepper, finely diced
4 cloves garlic, minced
1 1/4 cup grated Parmesan cheese, divided
10 large eggs
1 cup whole milk
1/2 cup yogurt
1 1/2 teaspoons salt
Freshly ground black pepper
Fresh parsley or basil, to garnish
Preheat the oven to 350°F and lightly grease a 9x13-inch, 3-quart baking dish with baking spray or olive oil.
Place the potatoes in a large microwave-safe bowl and add 1 cup water. Cover and microwave for 5 to 7 minutes, or until the potatoes are just tender. (You can steam them on the stovetop instead of cooking in the microwave, if you prefer.)
Drain the potatoes. Spread half of them in the bottom of the prepared baking dish. Mix together the bell pepper, garlic, and 1/2 cup of the Parmesan cheese. Spread this mix over the potatoes.
Whisk together the eggs, then whisk in the milk, yogurt, and 1/2 cup Parmesan cheese. Season with the salt and a generous quantity of black pepper. Pour about half of this egg mixture over the potatoes.
Lay the rest of the potatoes on top in neat overlapping rows. Pour the rest of the egg mixture over the potatoes, and top with the remaining 1/4 cup Parmesan cheese.
Bake uncovered for 50 to 60 minutes or until the egg is puffed and golden around the edges and fully cooked in the center. Sprinkle with chopped parsley or basil. Let cool for 5 to 10 minutes before serving.