Put liver pcs. in a bowl with your milk and soak for 45 min-1 hour.
Set Instant Pot to saute and add butter, garlic salt, diced bacon and onions. Saute until onions are softened. Remove from pot. Turn pressure cooker off/cancel.
Put flour on a plate and put 1 piece of liver on top of the flour, sprinkle with salt and pepper, then flip over and do the same thing so both sides are coated.
Turn Instant Pot to saute, normal setting, again and add 1 tbsp of olive oil.
Place 2 pcs. of liver that has been coated in flour in the pot and sear/lightly brown both sides. Remove from pot. Do this to all pcs. of liver you are cooking. Add remaining olive oil with additional pcs. to avoid sticking to the pot.
Turn pressure cooker off/cancel. ** Deglaze your pot! Full instructions for this above recipe card but basically add 1/2 c. of your beef stock into the pot and use a spatula to scrape all the pcs of stuck on meat off the bottom of the pot so it doesn't trigger the burn message during the next step.
Pour onion/bacon mixture back into the pot followed by remaining 1/2 c of beef stock.
Lay seared liver pieces on top of everything and close your lid and steam valve.
Set to pressure high for 5 minutes. Do a natural release for 10 minutes when it is done, then release rest of steam.
Serve topped with additional onions and broth at bottom of the pot.
If you like the outsides crispy put liver pieces inside air fryer basket in Ninja Foodi, set to 400 degrees for 3-4 minutes until outsides are browned. Can do the same with CrispLid on Instant Pot or Crockpot express or put under broiler for a few minutes.