Cut the top off of the strawberries, then cut in half. 

Add the strawberries, lemon juice, 1 tablespoon water, and granulated artificial sweetener to the Instant Pot.  Lock the lid in place, make sure the valve is set to seal and cook on high pressure for 1 minute. 

Let the pressure release naturally. 

Mix together the cornstarch and 1 tablespoon water. 

Remove the lid and add the cornstarch mixture. Set the Instant Pot to saute and stir for 2 minutes, or until the mixture has thickened.