In a medium bowl, mix together the ground beef, salt, pepper, and onion powder.
Divide the mixture into three even balls (or 6 balls, if making really thin burgers!). Flatten them into patties. Wrap them in aluminum foil.
Add 1 ½ cups of water to the inner pot of the Instant Pot and place a trivet inside. Place your wrapped beef patties on the trivet.
Close the lid on your Instant Pot. Set the sealing valve. Cook the burgers at High Pressure for 10 minutes.
When the timer is done, do a quick release. Open the Instant Pot lid and carefully remove the cooked patties from the Instant Pot, using either tongs or a large spoon. Carefully remove the patties from the foil - watch out for any steam of hot splatters!
Assemble your burgers: Immediately add a slice of cheese on top of the hot cooked burgers so it melts a little. Add your thousand island dressing to the bottom bun. Add your tomato, lettuce, burger, cheese, and onion slice. Or use your favorite burger toppings!
The nutrition facts are estimated for the patties only, and do not include buns or toppings.
To make an In n Out Burger recipe, you'll want these toppings: