Pour water into Instant Pot®. Place wire trivet in pot and arrange the eggs on top of trivet. Place lid on pot and lock into place to seal. Press the Egg or Manual/Pressure Cook setting, or cook on High Pressure for 8 minutes. Use Quick Pressure Release. Peel eggs while running under cold water and place in a bowl of very cold water to chill.
Cut eggs in half lengthwise, remove yolks, and place in a small bowl. Add the mayonnaise, oil, and mustard and mash together until very smooth. Season with salt and pepper. Fill egg whites with yolk mixture and top with desired garnishes. Chill until ready to serve.
Notes
Variations: Spicy Asian Style: Replace the oil with Sriracha sauce. Top with sesame seeds. California Style: Replace mayonnaise with mashed ripened avocado. Top with crumbled bacon. South of the Border Style: Replace oil with hot sauce, of choice. Top with a thin slice of jalapeno pepper.