Preheat the oven: Set to 375°F (190°C). Grease a 9-inch pie dish or a similar baking dish. If using a crust, fit it into the dish and crimp the edges. Prick the base with a fork.

Blind bake the crust (optional but recommended): Bake the empty crust for 8–10 minutes to prevent sogginess. Remove and set aside. If going crustless, skip this step.

Sauté the veggies: Heat olive oil in a skillet over medium. Add onions and peppers first, cook 3–4 minutes, then add mushrooms and cook until moisture evaporates. Stir in spinach last until wilted. Season lightly with salt and pepper. Let cool slightly.

Prepare the protein: If using turkey sausage or bacon, cook and crumble. If using chicken, dice it into small pieces. You want bite-sized bits that distribute evenly.

Blend the custard: In a blender or mixing bowl, combine eggs, cottage cheese or Greek yogurt, milk, salt, pepper, garlic, and paprika. Blend or whisk until smooth and frothy, about 20–30 seconds. This step makes the quiche custardy and light.

Assemble: Scatter the cooked protein and veggies evenly in the dish. Sprinkle most of the shredded cheese over the top, reserving a small handful. Pour the egg mixture over everything. Tap the dish gently to release air bubbles. Sprinkle the remaining cheese and herbs on top.

Bake: Place on the middle rack and bake 30–40 minutes, until the center is just set and the top is lightly golden. A knife inserted near the center should come out mostly clean with a slight wobble.

Rest and slice: Let the quiche cool for 10–15 minutes before slicing. This helps it set up and slice cleanly.

Serve: Enjoy warm or at room temperature. Pair with a side salad or fresh fruit for a balanced meal.