Here’s the problem: Despite the pot’s high-moisture environment, boneless, skinless chicken breasts dry out and turn to shards in a multi-cooker. So here’s our solution: Brown them first, then set them on a rack (or the machine’s trivet) to keep them off the insert’s superheated bottom when they undergo all that pressure. After cooking, a modified quick release lets them then sit in the steam a bit, so they can plump as they reabsorb some of their natural liquids.
Notice that these boneless skinless breasts are a bit larger than those sold in bulk bags at the supermarket. Notice, too, that you should brown the meat thoroughly. The chicken needs good color for the best flavor.