Cook the linguine according to the package instructions, then drain and set aside.
In a large skillet over medium heat, cook the ground beef until browned and cooked through. Drain excess fat.
Add minced garlic to the skillet and cook for about a minute. Stir in brown sugar, beef broth, soy sauce, hoisin sauce, ground ginger, black pepper, and red pepper flakes. Mix well.
Mix cornstarch with water to form a slurry and add to the skillet. Stir continuously until the sauce thickens, about 2–3 minutes.
Add the cooked linguine to the skillet and toss to coat the noodles in the sauce.
Garnish with sliced green onions and serve hot.