Begin by bringing a large pot of salted water to a boil. Add the linguine and cook according to package instructions until al dente, approximately 8-10 minutes. Drain the pasta and set aside.

In a large skillet over medium heat, add the ground beef, breaking it apart. Cook for 5-7 minutes until browned. Drain excess fat, leaving enough to keep the meat moist.

Add minced garlic to the browned beef and sauté for approximately 1 minute until fragrant, but not browned.

Reduce heat slightly and stir in brown sugar, beef broth, soy sauce, hoisin sauce, ground ginger, black pepper, and red pepper flakes. Let simmer for 3-5 minutes, allowing flavors to meld.

Mix cornstarch with water to create a slurry. Pour this into the skillet and stir constantly for 2-3 minutes until sauce thickens to desired consistency.

Gently add the cooked linguine to the skillet, tossing to coat. Heat for 1-2 minutes.

Remove from heat and serve topped with slices of green onions.