The broiled onion needs to be really black, all the way through, so that it’s dry enough to turn into powder to mix in this compound butter from Rose's Luxury. Things get smoky—open a window first!
Recipe information
Yield
Makes about 1 cup
Ingredients
1
1
½
special equipment:
Need to make a substitution?
Preparation
Step 1
Heat oil in a medium skillet over medium heat. Add chopped onion; season with salt and pepper and cook, stirring occasionally and adding 1 Tbsp. water to skillet if onion on bottom is getting too dark, until deeply browned and very soft, 20–25 minutes. Let cool.
Step 2
Mix butter and caramelized onion in a medium bowl; season with salt, transfer to ramekin and smooth top.
Step 3
Meanwhile, heat broiler. Broil sliced onion in a single layer on a broiler-proof baking sheet, turning occasionally, until dry and completely blackened, 12–15 minutes. Let cool, then grind to a powder in a spice mill or with a mortar and pestle.
Step 4
Dust butter with burnt onion powder.
Step 5
DO AHEAD: Onion butter (without onion powder) can be made 2 days ahead. Cover and chill. Sprinkle with onion powder just before serving.