Combine all ingredients for the stir fry sauce in a small mixing bowl and stir together until the coconut sugar has fully dissolved. Set aside.
Add 1 tbsp of olive oil to a large skillet and heat over medium heat. Add the broccoli florets, cover with a lid, and sauté for 5-6 minutes, stirring several times until broccoli is tender but still crisp. Remove the broccoli from the pan and set aside.
While the broccoli is cooking, thinly slice the flank steak into ⅛-inch slices. Cut against the grain, then cut the slices into bite sized pieces, and set aside.
Increase the heat to high and add the remaining 1 tbsp oil to the skillet. Add the sliced beef in a single layer and sauté for about 5-6 min, stirring throughout so that the meat cooks on all sides. Once the meat is fully cooked, drain any excess liquid from the pan if needed.
Add the sauce to the skillet with the meat and reduce the heat to a low/medium. Simmer for 3-4 minutes, or until the sauce thickens, stirring occasionally. Add the broccoli and stir to combine. Sprinkle with sesame seeds and serve immediately over cauliflower rice or white rice.