Set Instant Pot on "sauté", high. Allow pot to get hot and then add 2 tablespoon of olive oil, reserve remaining amount. Add half of the green onions to pot, along with half of the ginger root and half of the garlic. Use a wooden spoon and stir for about 2 minutes until ingredients are softened. Press "keep warm/cancel" button on instant pot.
Place lentils in the Instant Pot and add about 2 cups broth (enough to slightly more than cover the lentils), place cover on and make sure vent knob is in "sealing" position. Select "manual" setting, adjust time to 15 minutes. Allow to vent naturally at end of cycle. Take lentils out of pot and transfer to glass dish and cover with foil.
Set Instant Pot on "sauté", high setting. Add 1 tablespoon olive oil and butter to pot and allow to get hot. Next, discard the marinade and add beef chunks and stir with wooden spoon to evenly brown. Add remaining green onions, ginger and garlic. Stir for about a minute and then add flour. Stir contents to coat with flour and add about 1 cup (remaining) broth. Stir well and place cover on instant pot.
Set to "meat/stew" for five minutes, be sure vent knob is in "sealing" position. Allow to vent naturally at end of cycle.
Serve the stew over lentils and garnish with thinly sliced stems from green onions if desired.
Use 1 to 1.5 lbs of beef, you may substitute stewing beef for the sirloin. If using a lesser grade of beef such as stewing beef, allow for 15 minutes of time, on "meat/stew" cycle.
You may use beef or vegetable broth or water instead of chicken broth.