Start by heating up the pressure cooker. For the IPPC (Instant Pot Pressure Cookethat is the Saute’ function. Place the butter and oil in the inner pot. A couple of minutes
When the butter starts to brown add onion. The onion should be finely chopped. Stir the onion until it is starting to get soft. Add the hamburger and cook until just falling apart and lightly browned. Maybe 5 minutes.
Add garlic, mushrooms, lemon, beef stock, salt and pepper. I didn’t think it needed and salt so I just added the ground pepper. I would add maybe a tsp of beef bouillon to increase the beef taste and add the little salt that might be needed. Put on the lid and cook for 15 minutes. Use natural pressure release for 5 minutes and then quick release the rest of the pressure.
Add the 8 oz of sour cream. Serve with noodles.
I have an Instant Pot Pressure Cooker but you should be able to use this recipe without modification other than terms for the different pressure cookers functions.