In a small bowl, mix the softened butter (soft, not melted) with the white miso, grated garlic, and parsley or chives until smooth. Refrigerate to set while you prep the mushrooms.
3 tablespoons unsalted butter, 1 tablespoon white miso, 1 clove garlic, 1 tablespoon fresh parsley
Wipe the shiitake mushrooms clean with a damp paper towel, remove the stems, and slice the caps.
2 cups shiitake mushrooms
Heat a large skillet over medium-high heat. Do not add any oil.
Add the mushrooms in a single layer. They will release their moisture first, then start to brown as it cooks off. Stir occasionally and cook 6 to 8 minutes, until golden brown.
Add 1 to 2 tablespoons of the miso butter and toss for about 1 minute, until melted and glossy.
You don't have to use all the miso butter. Add 1 to 2 tablespoons and save the rest. Keep it in the freezer until next use.
Finish with freshly cracked black pepper. Taste and adjust before serving.
freshly cracked black pepper