Adapted from The Greens Cook Book by Deborah Madison and Edward Espe Brown. This is a wonderful pasta dish with a flavorful mushroom/pasta base and a rich bechamel sauce. It's a satisfying meatless (but not dairy-free) main dish.
Cover the dried mushrooms with 1 cup boiling water and let them sit for 20 minutes. Squeeze them dry, saving the soaking liquid, and roughly chop them into small pieces.
Warm the butter and olive oil with the bay leaves over medium heat in a large skillet or dutch oven. Add the onion, carrots, celery, and herbs, raise the heat, and cook briskly, stirring frequently, for 3-4 minutes.
Add the sliced fresh mushrooms, the garlic, and the dried mushrooms. Season with salt and cook 3 minutes, then add the soaking liquid from the mushrooms and the tomato puree or paste. Cook until the mushrooms are tender and a syrupy juice remains on the bottom of the pan. Season with pepper and salt, if needed.
For the bechamel, melt the butter in a saucepan, add the shallot or onion, and cook slowly until it is soft. Stir in the flour to make a roux, and cook gently over a low heat for 3-4 minutes, then set it aside to cool. Combine the milk and the cream, and heat nearly to the boiling point, then whisk into the cooled roux. Return the pot to the heat and cook 15-20 minutes, stirring frequently. Season with a few scrapings of nutmeg, and salt and pepper to taste.
Preheat oven to 375F and grease a 9X13" baking pan. Pour 1/2 c of bechamel in the bottom, then lay down enough cooked lasagne noodles to cover the bottom of the pan (about 3). Spread another 1/2 c of bechamel on the pasta layer, a quarter of the mushrooms, and some grated cheese. Repeat in this fashion, making four layers in all.
Cover the lasagne loosely with foil and bake for 15 minutes. Remove the foil and continue baking until the top is puffed and browned, about 25 minutes.
Allow the lasagne to rest a few minutes, then cut into 8 pieces and serve.
Note: If you're not in the mood to do the layering required by lasagne recipes, you can use whatever shape of pasta you like (penne rigate works well) and axe the layers. After placing the 1/2 c of bechamel in the bottom of the pan, pour all of your cooked pasta in, then cover with the mushroom mixture, and finish it off with the remaining bechamel, and top with the cheese.