Let the lasagna rest uncovered for 15-20 minutes to avoid a sloppy mess. Better still (if you have the time), consider making your lasagna a day ahead of time and reheating to serve.

Why does lasagna need to rest?

Letting the lasagna rest allows everything to calm down in there. It lets it set a bit. Then when you cut into it, it can hold together better. It's going to taste better too when the first bite doesn't scald your tongue.

Should lasagna be cooked the day before serving?

Answer: If you assemble and bake the lasagna ahead of time, you shouldn't keep it longer than three days in the refrigerator. If you need to keep it longer, it would be better to freeze it and reheat it. If you just need to make it a day ahead, you could refrigerate it before baking it.