Asparagus is one of my favorite culinary ways to welcome spring. I almost always make this recipe for Passover, which falls at just the right time of year. It would also be great for Easter for the same reason. This is a pretty flexible dish -- you can play with quantities, change up the onions, etc. and it still turns out delicious. I have been replacing much of the butter with olive oil, and that works fine too. Cooking time assumes pre-trimmed and pre-cooked asparagus, though what I usually do is trim it (it's more tender if you break it wherever it breaks naturally than if you cut it) and start it steaming, then make the sauce.