Sauté: Add 2 tablespoons of peanut oil and 1 teaspoon of sesame oil to the Instant Pot, then select the sauté setting. When the oil is hot and shimmering, add the beef. Cook while stirring frequently until the meat is browned, about 3 minutes. Add the white part of the green onions, along with the garlic and ginger; sauté for an additional 1 minute. 

Add Seasonings: Cancel the sauté setting and add the remaining sesame oil, beef stock, soy sauce, oyster sauce, brown sugar, and chili paste to the beef. Stir to combine. 

Pressure Cook: Place the lid on the pot and turn the know to “sealing” (this is automatic on many cookers). Set it to pressure cook on high pressure for 8 minutes. When the time is up, carefully do a quick release. 

Cook the Broccoli: While the beef cooks, put the broccoli in a saucepan with about 1/2 cup of water. Cover the pot and bring to a boil. Reduce the heat to low and steam for about 2 to 3 minutes, or until tender. Transfer the broccoli to a colander to drain, then rinse it with cold water to stop the cooking process. 

Make the Cornstarch Slurry:  Combine the cornstarch with 2 tablespoons of cold water in a small bowl or cup. Mix until smooth. 

Finish the Dish: Cancel the "keep warm" setting and set the pot to "sauté". Add the cornstarch mixture to the pot and cook, gently stirring, for about 1 minute, or until the sauce has thickened. Add the broccoli and heat through. Transfer the beef and broccoli to a serving bowl and sprinkle with the sliced dark green onion tops.