Freeze steak for 30 minutes to make it easier to slice. Cut broccoli into florets and set aside.
Stir Fry Sauce: In a medium bowl whisk together soy sauce, chicken stock, brown sugar, cornstarch, garlic, ginger, sesame oil, and crushed red pepper. Set aside.
Remove the steak from the freezer and slice it thinly into bite sized pieces.
Heat 2 tablespoons olive oil in a large skillet over medium heat. Add in the broccoli and sauté for 5 minutes, or until crisp-tender. Remove from the pan.
Add the remaining tablespoon of olive oil into the pan and turn the heat up to high. Add the sliced beef in 2 batches, cooking for 2 minutes, until browned. Remove from the heat and add the remaining beef.
Turn the pan down to medium, add all the beef back to the pan, and pour in the prepared sauce. Stir to combine, and bring to a boil. Simmer for 3 – 4 minutes until slightly thickened. Add the broccoli back to the pan and stir to coat in the sauce. If the sauce gets too thick add in 1 – 2 tablespoons of water (or chicken stock) to thin it out.
Serve over white rice and garnish with sesame seeds and chives.
