You can make this beef and broccoli stir fry dinner in under half an hour. Cook your rice while you are making this stir fry.
For the sauce, combine the flour, beef broth, soy sauce, oyster sauce, red pepper flakes & brown sugar in a small bowl.
Whisk until well-mixed. Set aside.
Heat olive oil over medium heat in a large pan. Add the garlic once the oil is hot, and let cook until softened.
Add the beef and stir-fry for about 2-4 minutes, or until the beef is halfway cooked.
Add the broccoli and stir-fry for about 2-4 minutes.
Add the sauce and bring to a boil. Reduce heat and allow it to simmer for about 5 minutes, or until the sauce has slightly thickened.
Season with salt and pepper to your taste.
Serve with rice.