4 large eggs, lightly beaten (or 1 cup egg substitute)
1 teaspoon salt
1 teaspoon baking powder
2 teaspoons spicy mustard (or Dijon mustard)
1/4 teaspoon ground black pepper
1/8 teaspoon ground nutmeg
1/8 teaspoon ground red pepper
Preheat oven to 350˚F. Pour melted butter into the bottom of a 13 x 9-inch baking dish or pan coated with cooking spray; tilt dish or pan to coat. Place spinach evenly in bottom of dish or pan and sprinkle evenly with the cheddar and Monterey Jack cheeses.
In a medium size bowl, combine flour and remaining ingredients, stirring with a whisk until blended. Pour this mixture over spinach and cheese in pan. (Note: As you are making this, it may seem like there’s too much spinach and cheese, because it definitely fills up the pan–but put all of it in there! Because when you mix the egg-milk mixture and pour it over the spinach and cheese, that will weigh it down. Before you put this Cheesy Spinach bake in the oven, it will look like what is shown in the small picture.)
Bake at 350˚F for 40 minutes or until lightly browned. Let set for about 5 minutes, then cut and serve.