How to Make It
Select SAUTÉ on Instant Pot, and add butter and oil. When butter is melted, add onions and sugar; stir well to coat. Select CANCEL.
Cover cooker with lid, and lock in place. Turn steam valve to SEALING position. Cook on HIGH PRESSURE for 5 minutes (pot will take 7 to 10 minutes to build pressure).
Select CANCEL, and carefully release pressure. Remove lid, and select SAUTÉ and NORMAL setting to 18 minutes. Cook, stirring occasionally, until onions are caramelized. Sprinkle with salt and pepper.