I was really aiming to impress with this dish, which is why I made an attempt at frying the sage for a garnish while the lasagna baked in the oven. I ended up burning the sage, and throwing it away. In retrospect, I probably should have chopped the sage and mixed it in with the ricotta and Boursin cheese. In retrospect, I actually wouldn't even use the Boursin cheese. Baking it for so long in the oven prevented its delicate flavor from having any kind of impact. In the end, this lasagna left a great impression (nobody at the dinner party, including me, had ever had pumpkin in a lasagna before, and, in fact, some had never even eaten a real pumpkin!). Nonetheless, I would use a little more ricotta in lieu of the Boursin, which you could always eat with crackers and wine beforehand. And don't burn the sage unless you're smudging the house, which I would not do in a frying pan, and certainly not during a dinner party.
1 medium sugar pumpkin, peeled and cubed
2 portabella mushrooms, chopped
1 package of spinach, chopped
2 shallots, diced
Half & half
Boursin garlic and fine herb cheese
1 package of No Boil Lasagna
Salt & Pepper
Preheat the oven to 400 degrees, and get to work preparing your lasagna layers:
Braise the pumpkin using olive oil, then water (don't forget to season with salt & pepper).
Sauté the shallots, then the mushrooms, then the spinach (cooking each ingredient until its liquid is released, then reduced--don't forget to season with salt & pepper).
Mix together the ricotta and chopped sage (even season that with at least a little salt & pepper).
Prepare a Béchamel sauce by first melting half a stick of butter in the pan. Then combine four tablespoons flour (always equal parts flour and butter). Cook this until it forms a paste, stirring constantly so that it bubbles, but doesn't brown. Then gradually whisk in the entire container of half & half (I let this sit out for a little while so that it doesn't go into the pan cold). Allow the sauce to thicken and come to a gentle boil. Season with salt, pepper, and nutmeg to taste, and cook for two more minutes, still stirring. Remove from heat and stir in Parmesan cheese (also to taste).
Finally, layer the ingredients in a lasagna-shaped casserole dish. I started with the Béchamel at the bottom of the dish, then lasagna noodles, then ricotta (I had never used no bake lasagna before, and got the impression that the pasta should be surrounded by the most liquid ingredients. I'm not sure if this is the general rule, but it worked out great), then pumpkin, then the mushroom and spinach mixture. Continue layering until you reach the top of the dish. Finish with a final layer of Béchamel and sliced Mozzarella.
Cover in foil and bake for about 40 minutes. Remove the foil and bake for 15-20 minutes. If the top isn't brown by then, turn on the broiler, and check on it every minute or so until the top looks as brown as you like. Remove lasagna from the oven and let cool for 15-20 minutes.