Cut all cauliflower florets to about the same size.
Place a pot of water on the stove with a steamer basket insert, bring to a boil. Add florets to steamer basket and cover. Cook for 10 minutes or until very tender.
In a small bowl whisk together miso and melted butter, if too thick add a bit of warm water, whisk until well combined.
Place cauliflower in a blender with miso butter mixture and a generous pinch of salt and pepper. Blend until smooth and creamy. Add a splash of water if mixture is too thick.
Alternatively, you can use a food processor, immersion blender, or a masher to mash and combine ingredients.
Serve with reserved chopped scallions, a sprinkle of flaky sea salt, and additional black pepper.
