Ina Garten's recipe for portabello mushroom lasagna, but tweaked it in the following ways:
1. I added more veggies: leeks, spinach, and garlic (never use frozen spinach in lasagna, always microwaved fresh - frozen is too tough, strong-tasting, and wet).
2. I added a second type of cheese: mozzarella (for this dish I recommend sticking to just parmesan because the dish relies on the stronger, salty flavor of parm - I just bought moz on accident because I originally was making a tomato sauce lasagna).
3. I added thyme to the mushrooms and leeks as well as a splash of balsamic vinegar at the end of sauteeing because I thought they needed all the flavor boost they could get, this being a béchamel lasagna.
Turned out pretty well but I'm partial to tomato-based lasagnas!