Basically Skillet Lasagna

Finally: an easy, cheesy, vegetarian(!) lasagna recipe that doesn't require you to dirty every pot and pan in your kitchen. But that's not all! It also comes together in just over an hour and, thanks to all that frozen spinach, delivers enough veggie goodness to justify eating a big pan of baked pasta on a Tuesday. If you don't have a cast-iron skillet, don't sweat—any sturdy, similarly-sized pan that has a heatproof handle will work almost as well here.