Prepare the marinade. You can use the recipe above for reference. But if you’ve got your own favorite recipe for marinade, then feel free to use it!
Place the marinade you’ve prepared into a bowl and then arrange the London broil cut into the bowl with the marinade.
After mixing the ingredients above, add a small amount of chopped shallots, peeled garlic cloves, oregano, and thyme.
Turn the meat over to ensure that it’s fully coated with the marinade. Cover and place overnight in the fridge.
Take the steak out of the bowl with marinade.
Cut the meat in half and place it into the pressure cooker.
Set the pressure cooker to “browning” or “sauté”.
Coat the bottom of the pressure cooker with a generous amount of oil.
Place the steak in the pressure cooker. Brown the steak quickly. Use a pair of tongs to turn them over.
Press the cancel button and put down the lid of the cooker. Make sure that the vent is fully closed.
Use the "manual" setting. Depending on the type of pressure cooker you’re using, you might have to choose a different designation, so follow the instructions very carefully.
Set the cooker to cook according to the manufacturer's instructions. The cooking time for the Instant Pot is usually 20 minutes for every lb of steak at 12 “pounds per square inch” or around 15 minutes for every lb of steak at 15 “pounds per square inch.” It’s worth noting that if the PSI is high, the temperature inside the cooker is high as well.
After the proper cooking time is achieved, press the cooker’s quick-release function.
If you believe that the London broil has already been adequately cooked, remove it from the cooker and place iti on a platter.
Let it sit for a while to keep the steak moist.