In a large bowl, combine beef, ranch seasoning, worcestershire and cheddar cheese until uniform.
Shape into 4 patties and wrap each patty individually in foil, sealing the edges.
Pour 1 1/2 cups of water in the Instant Pot and insert the steam rack. Place foil packets on the rack (3 on the bottom and one on top).
Secure the lid, making sure the vent is closed.
Using the display panel select the MANUAL or PRESSURE COOK function*. Use the +/- keys and program the Instant Pot for 10 minutes.
When the time is up, quick-release the pressure.
Carefully remove the packets from the pot, remove the rack and discard water.
(Optional) Coat the inside of the pot with nonstick spray. Using the display panel select the SAUTE function. Brown the burgers on both sides, 2 minutes per side.
Serve burgers on toasted buns with toppings of your choice.
Notes
*The MANUAL and PRESSURE COOK buttons are interchangeable.