Step 1

Add onions, butter, 2 teaspoons salt, and 1/2 teaspoon pepper to the bowl of a multicooker; stir to combine. Secure the lid and adjust vent to seal. Cook on high "Pressure Cook" setting for 5 minutes. Once cycle is complete, immediately release pressure. Carefully remove lid.

Step 2

Strain onions and discard excess liquid. Return onions to multicooker. Cook over high "Saute" setting, stirring constantly, until onions are deeply golden and caramelized, 3 to 5 minutes. Store in an airtight container in the refrigerator for up to 1 week.