This is an awesome lasagna. I’m not kidding, it’s really, really good. Unless you don’t like mushrooms, of course, in which case I can’t help you. This is all about the mushrooms. And the cheese.
I got the idea for this lasagna from a recipe in Deborah Madison’s Vegetarian Cooking for Everyone, but I embellished it a bit with extra cheese and a generous amount of sausage, because I tend to feel that sausage makes everything better. One technique of hers that I think is really key here is adding the porcini soaking liquid to the bechamel. It gives the creamy sauce an earthy perfume that I find irresistible.