You can throw practically anything into a frittata, from day-old fried rice to veggies that need to be used before they go bad. Unlike quiches, frittatas are crustless, less fussy to make, and can be served at any time in the day, but there’s an important ratio to keep in mind for a creamy frittata with a bit of a jiggle and no watery spots.

While you can wing it when it comes to frittata add-ins, you must pay attention to your egg-to-dairy proportions. For quiches, the egg-to-dairy ratio is one egg to a ½ cup of dairy, which creates a rich custard, but the consistency of a frittata is drier and fluffier, and requires a base ratio of a dozen eggs to just a ½ cup of dairy.

The high proportion of eggs to dairy results in a frittata that resembles an omelet more than a custard. The cooking time for frittata is also relatively brief and depends both on the size of your frittata and the size of your skillet; make sure to remove your frittata from the oven when it gives a slight jiggle when shaken, to avoid overcooking.