Pour the water into the insert set in a 5-, 6-, or 8-quart Instant Pot. Put a pressure-safe rack or trivet in the insert.
Stir the fruit, sugar, cornstarch, cinnamon, and salt in a 2-quart, 7-inch-round, high-sided, pressure-safe baking or soufflé dish until the fruit is evenly coated in the sugar and cornstarch. Cover the dish tightly with aluminum foil, set the dish on the rack, and lock the lid on the pot.
Set the Instant Pot for Pressure Cook/Manual for High Pressure for 12 minutes.
When the pot has finished cooking, turn it off and let the pressure return to normal naturally for 10 minutes. Then use the quick- release method to get rid of any residual pressure in the pot. Unlatch the lid and open the cooker. Use hot pads or silicone baking mitts to transfer the (hot!) baking dish to a nearby wire rack. Cool for 5 minutes, then divide the fruit mixture among four serving bowls and top each with 1/2 cup granola.