In a small bowl, whisk together the coconut aminos, broth, coconut sugar, toasted sesame oil, fish sauce, garlic, ginger and red pepper flakes until well combined. Pour into the InstantPot.
Slice the sirloin steak into thin strips, about ¼-inch thick. For longer strips, you can cut them in half so they aren’t super long. Sprinkle the steak with salt and pepper and toss to evenly combine.
Add the seasoned steak slices to the slow cooker and toss so that it is evenly coated in the sauce. Cover and make sure the InstantPot is sealed and the valve is sealed. Select Manual High Pressure and cook for 12 minutes. Walk away and let the InstantPot do its thing until cook time is complete.
When the cook time is complete, turn the valve to release the pressure. When the pressure is released, carefully open the InstantPot. Stir the beef and then scoop about ¼ cup of the liquid from the slow cooker. Add the tapioca flour and whisk until well combined to make a slurry.
While stirring, slowly pour in the slurry until well combined. The sauce should begin to thicken. Stir in the broccoli, cover and keep the InstantPot on ‘warm’ until the broccoli is tender and the sauce has thickened, about 10 to 15 minutes.
Serve in bowls over rice or cauliflower rice, if desired, and garnished with toasted sesame seeds.