1.5ozdried morel mushroomsabout two cups of dried morels depending on size, I really suggest using a scale since they vary, especially if you have gigantic Midwestern morels.
1lbunsalted buttercut into ~1x1 inch cubes, at room temperature
1tablespoonflavorless oillike grapeseed
1small shallotdiced 1/4 inch
1teaspoonchopped fresh thymeoptional
Re-hydrate the morels in the water until softened, about 20 minutes. Agitate the morels in the water to remove any grit, then remove the morels, strain the liquid, then coarsely chop the morels. Reserve 1/4 of the morels for garnish.
Heat the shallot and the oil in a saute pan until the shallot is translucent, about 3 minutes on medium heat. Add the sherry and cook until reduced by half.
Add the morels, their strained liquid along with the thyme and bring the mixture to a simmer, for 10 minutes to reduce the liquid a bit.
Transfer the mixture to a blender or use a hand blender or a food processor to finely puree the mixture.
Season the puree with the salt, mix to combine, and cool to room temperature to avoid breaking the emulsion of the butter. When the puree is cool, whisk it in a bowl with the room temperature butter and the reserved morels or whip in a stand mixer.
It's important to really whip it a bit, since it incorporates air into the butter, similar to when you would make whipped cream. If I want to make fluffy butter to spread on bread, I may add an ice cube or two while it's in the stand mixer, which adds a little extra fluff.
When evenly mixed and fluffy, transfer the butter with a spatula to parchment or wax paper and roll tightly into a log, then tie the ends closed with string or plastic wrap.
Label, date, and freeze the butter until needed. The butter can be kept in the fridge, and will keep for a week. If you're not going to use the butter in a few days, keep it in the freezer, then you can pull out the log(s), allow to thaw a bit, then cut off pieces as needed and return them to the freezer.