Preheat oven to 375F and spray or grease a large oven-safe skillet (I (I use a Le Creuset Enameled Cast-Iron 10-¼-Inch Skillet , skillets from 9 to 12 inches in diameter will work, or a 9-by-9-inch baking pan). Lightly place about 3 cups hash browns in the skillet, covering the base in a uniform layer. Add the soup over the top of the potatoes and spread it uniformly using a spatula because it's thick. Optionally, sprinkle cheese and/or vegetables or beans.

Pour eggs evenly over the top, and add 1 cup remaining hash browns, lightly sprinkled uniformly over the top. Drizzle with olive oil, sprinkle with seasoning blend, and sprinkle with salt and pepper to taste.

Bake for about 50 minutes, or until golden browned on top and edges have crisped up. Remember that if cooking in cast iron, there is a notable carryover cooking effect so food will continue to cook in the skillet and don't wait to pull frittata from oven until it's very browned because with carryover cooking factored in, it may become over-done. Allow frittata to cool in the skillet for at least 10 minutes before slicing and serving, which allows it to set up and will be less messy when sliced. Leftover frittata may be wrapped in plasticwrap or stored in an airtight container in the refrigerator for up to 3 days.

Frittata is vegetarian and gluten-free, provided soup used, or any optional ingredients used, are vegetarian and gluten-free.