Adapted from Marlene Sorosky
2 pounds fresh spinach (about 10 ounces)3 eggs1/2 cup all-purpose flour1 cup milk1/2 teaspoon salt, or to taste1/4 teaspoon pepper1 teaspoon baking powder1/2 teaspoon hot pepper sauce (I use Sriracha), or to taste1 pound jack cheese, shredded (about 4 cups)3 tablespoons butter
Place your baking rack in the center of your oven and preheat to 350F/175C.
Remove the stems from spinach. Wash and tear leaves into bite-size pieces, then dry very well.
Using a large bowl, whisk the eggs together until frothy. Whisk in flour until combined. Next, add the milk, salt, pepper, baking powder and hot pepper sauce and whisk. Mix in cheese and spinach (there will be a lot compared to the amount of egg mixture).
Use the butter to grease a 9- or 10-inch quiche dish or 7-by-11-inch casserole dish. Place in oven until butter has melted. Pour spinach mixture into heated dish. Place dish on a baking sheet and bake for 45 to 55 minutes or until puffed and golden brown. Cool 10 minutes. While the frittata cools it will fall. Once cooled, cut the frittata into wedges and serve.