To set the color of the asparagus, we dropped them in a large pot of boiling, salted water for just a minute, then rinsed them in cold water to stop them from cooking any further. Don't drain away the water though to get at the asparagus - just fish them out with a slotted spoon. This way, you can cook the lasagna noodles in the same batch of seasoned water.
While the noodles were busy, we started creating the sauce we were going to smother this dish with. Butter, melted into a golden pool, gave us a spot to soften a finely chopped onion before we sprinkled in the flour used to thicken the sauce. Make sure you stir that flour around for a minute or two, giving it a chance to cook out its raw pastiness. Using entirely milk as the liquid for the sauce gives you a silky mouthfeel - however, you could use equal amounts of milk and broth to make the sauce a little lighter. To make sure the flour has been activated to thicken the milk, be sure it comes up to at least a boil. After stirring in a duo of cheeses, fresh grated Asiago and Parmesan, our milk sauce turned into a cheesy pool that was ready to be lifted with a bit of fresh grated nutmeg (try not to leave this out as it adds an intriguing complexity that works well in a white sauce).
Built as a typical lasagna, the assembly included the cheese sauce, noodles, thinly sliced ham, the crisp-tender asparagus and a bit more Asiago and Parmesan in each layer. To trap the moisture inside, creating a steamy package to finish the noodles off and warm through the dish, we covered the top with foil just before we placed the heavy dish into the oven. While it could be considered done after a half hour, to finish off the top layer, that foil is removed during the last ten minutes of baking. You could serve this pipping hot out of the oven, but I highly suggest setting aside an extra fifteen or so minutes to let this lasagna meld and cool down first. This gives the sauce a chance to set, allowing you to pull out slices that don't slip and slide off your plate!
Lasagnas loaded with meat and tons of cheese are certainly lip-smackingly delicious, but they can also come across as being heavy and quite rich, which doesn't always sit too well during the warmth of spring or summer. What Jeff and I both liked about this version was how clean and refreshing it felt, with the lighter ham, tender fresh asparagus and nutty cheese blend. It also happened to make plenty to go around, leaving us with a few nice lunches to look forward to!