In a small bowl, mash together the ghee (or butter) and miso paste until smooth.
You can use it right away. If making a larger batch, shape it into a log (like compound butter) using plastic wrap, then refrigerate or freeze for later use.
Fresh miso butter keeps well in the fridge for 2–3 weeks or in the freezer for up to 3 months. For easy defrosting, flash-freeze the butter in small ice cube trays. Once solid, transfer to a freezer-safe bag for later.
Use it just like you would butter (a small amount goes a long way) —spread on bread, melt over warm pasta, stir into ramen soup, rub onto winter squash before roasting, or add to steak, shrimp, or fish for an instant flavor boost.
Notes
Ratio: Use 2 parts butter to 1 part miso paste. This makes it easy to scale the recipe up or down.
Softened butter: Always start with softened butter for easy blending. If using regular butter, microwave it on medium in 20-second intervals until softened (not melted).
Bigger batches: For large quantities, use a food processor to get a smoother, more even mix.