In a medium bowl, whisk together all the ingredients listed in the Sauce compartment. Set aside.
Press Sauté on the Instant Pot and wait for the Instant Pot indicator to read "HOT".
Add vegetable oil; once the oil is hot, add the beef in one layer (in batches). Do not move or turn the beef for about 2 minutes to ensure it gets a nice sear on one side (this is important).
Stir the meat and sauté for 2 minutes on the other side. Remove, set aside on a plate covered with foil, and brown another batch of beef. Set it aside.
Once the beef is browned, add 1/4 cup of water to the pot to deglaze it. Using a wooden spoon, try to get any bits and pieces that are stuck to the bottom of the pot.
Add the beef back to the pot, and pour the sauce mixture on top. Stir to combine.
Close the lid and pressure cook on High Pressure for 10 minutes, followed by a 10-minute Natural Release. After 10 minutes of NPR, turn off the Instant Pot. Release the remaining pressure. Open the lid.
In a small bowl, mix the cornstarch with water until it is thoroughly combined.
With the IP set to the Sauté function, add the slurry to the pot, stir to combine, and cook for 2-3 minutes on Sauté, stirring occasionally, until the sauce has thickened. If needed, add more slurry (1 tbsp cornstarch mixed with 1 tbsp water) until the desired thickness is achieved.
Stir in the steamed broccoli.
Turn off the Instant Pot and serve over rice or noodles. Garnish with fresh chopped green onions and sesame seeds.
