Start by mixing up the sauce. Add the soy sauce, hoisin, minced garlic, and red chili sauce to a bowl and whisk until combined. Set aside.
Next, place flank steak out on a cutting board and cover it with parchment paper. Use a meat tenderizer to tenderize the flank steak. Pound each side of the flank steak for 1-2 minutes or until it is 1/2 inch thick.
Slice your flank steak in half (hot dog way) and cut each half into about 3-inch long thin strips.
Turn on the Instant Pot's saute function and add olive oil to the pot. When olive oil is fragrant, add flank steak and cook for 2 minutes, stirring occasionally.
Turn off Instant Pot. Add sauce to the flank steak. Mix well and cover Instant Pot.
Cook the meat on high pressure for 8 minutes.
Quick release pressure and uncover Instant Pot. Transfer the broccoli to the pot with the flank steak.
Place the lid back on the Instant Pot and set the timer '0' minutes. The pressure will build and beep when it reaches full pressure. This is when you quick release the pressure again.
Remove the beef and broccoli from the Instant Pot, leaving the sauce. Add cornstarch to the sauce and whisk until there are no lumps.
Add beef and broccoli back into the Instant Pot and mix so all ingredients are coated with sauce.
Serve with white rice.