Soak the beans in a big bowl of water for at least 8 hours or up to 12 hours. Drain in a colander set in the sink.
Pour the beans into the cooker. Add enough water so they’re submerged by 2 inches. Add 1 tablespoon olive oil and lock the lid onto the cooker.
Optional 1Max Pressure Cooker Press Pressure cook on Max pressure for 10 minutes with the Keep Warm setting off.
Optional 2All Pressure Cookers Press Pressure cook (Manual) on High pressure for 12 minutes with the Keep Warm setting off.
As the beans cook, whisk the remaining 1⁄4 cup olive oil and the vinegar in a large, heat-safe serving bowl until smooth. Stir in the onion, parsley, garlic, capers, rosemary, salt, and red pepper flakes.
When the machine has finished cooking, use the quick-release method to bring the pot’s pressure back to normal. Unlatch the lid and open the cooker. Drain the contents of the hot insert into a colander set in the sink. Shake the colander to make sure the beans dry well. Dump them into the bowl with the dressing and toss well. Serve warm.