Lasagna is a labor of love. If I’m going to put in the effort, I want a spectacular result, and my standards are just as high when it comes to vegetarian versions of this Italian-American favorite.

This sophisticated butternut squash lasagna proves it’s possible to achieve delicious results without too much fuss. It’s a simple filling of sliced butternut squash, sautéed shallots, walnuts, and fresh sage that delivers lots of savory flavor. To make what is traditionally a heavy dish lighter, I make a rich and creamy béchamel using low-fat milk and olive oil instead of butter. A few key ingredients and techniques help keep the p...