Cut broccoli into florets, peel stalks and slice into thin coins. Set aside. Mix garlic, broth, soy sauce, cornstarch, brown sugar, sesame oil, and fish sauce in bowl. Set aside.Heat canola oil in large skillet. When oil is hot, add broccoli. Cook 4 minutes, stirring continuously, until broccoli is brown in places. Add 1/2 cup water, cover, and cook for an additional 4 minutes, until broccoli starts to get tender. Stir in sauce, cook for 2 more minutes until sauce starts to thicken and broccoli is cooked to your desired tenderness. Garnish with scallions if you'd like ad serve over rice.