In a medium bowl, mix together ground beef and turkey, bread crumbs, Parmesan, onion, egg, and milk.
Make the glaze. In a medium bowl, mix the ketchup, brown sugar, and Worcestershire sauce until blended.
Mold the ground beef into burger patties. Brush glaze over each patty.
Wrap each burger patty in a tin foil packet.
Pour one cup of water into the bottom of your Instant Pot. Place the trivet or sling in your Instant Pot and stack them.
Cover your Instant Pot and seal the valve. Cook on high pressure for 15 minutes. Let the pressure naturally release.
Prepare sliders and serve.