Using a recommendation out of the Vegetarian 5-ingredient Gourmet, we created a frittata of 4 eggs instead of the requested 3 and only 3/4 of the amount of spinach. More would have just been too much. We also added some finely chopped onions and replaced the Parmesan cheese with the Norwegian Swiss (Jarlsburg). Easy to mix, the meal cooked quickly and looked inviting with tomato slices and grated cheese garnish. The frittata filled the pan and quickly rose, requiring two people to flip it over. We actually, slid it over onto a plate, then turned the plate over onto the pan.