Begin to prep the garlic and the scallions first. Mince the garlic into a small dice. Also, wash and slice the scallions on a bias in thin slices. Set these both aside.
On the same cutting board, slice the beef into very thin slices. You can start with a partially frozen cut of beef (see notes above). Cut the beef into 3-4 strips. Then cut them into about 2”-3” x 3” thin slices. Place all the pieces into a large mixing bowl. Season the beef with kosher salt, coconut aminos, sesame oil, rice vinegar, and agave. Feel free to use other natural sweeteners like honey. Add the minced garlic to the beef. Give everything a good stir and allow it to marinate for 5 minutes.
Turn the Instant Pot on the “Saute” setting and wait until it says “Hot.” Add the avocado oil. Add the marinated beef. Give everything a good stir. Place the lid on the pot and set the pot on high pressure for 5 minutes.
Once the timer has finished, release the pressure. Turn the pot back on the Saute setting. The meat will release some liquid into the pot. You will want to thicken the sauce with a starch slurry. To do this, combine the arrowroot starch with two tablespoons of water. Add half of the mixture to the pot. Turn the pot on the Saute setting and wait until the mixture begins to bubble. Once bubbling, assess if the mixture has thickened and is coating the meat. If not, add the remaining slurry.
Add the broccoli into the pot. Give the mixture a good stir. Place the lid on the pot loosely for 1-2 minutes. Stir again. Cook until the broccoli is cooked through but still crunchy (or desired doneness). Serve hot with cauliflower rice.