First of all. Place onions and mushrooms in the bottom of the Instant Pot.
Step two, Combine beef patty ingredients and form 6 patties. Brown over medium high heat (about 3 minutes per side) in a skillet. *see note
And now, Layer beef patties over mushrooms. Combine remaining ingredients except water and cornstarch. Pour over beef and cook high pressure, 18 minutes.
Complete Ingredients and Instructions: https://www.spendwithpennies.com/instant-pot-salisbury-steak/