Cook 10 ounces udon noodles according to the package directions and drain. Set aside.

In a large skillet over medium-high heat, cook 1 pound lean ground beef until mostly browned. Add 4 cloves garlic and cook for a minute, until fragrant. Drain the excess fat.

While the beef is cooking, whisk together the ½ cup soy sauce, ¼ cup brown sugar, ¼ cup beef broth, 2 tablespoons hoisin sauce, 2 teaspoons ginger paste, and 1 teaspoon red pepper flakes.

Pour the sauce over the meat and finish cooking the ground beef in the sauce. Add the noodles to the pan with the beef and sauce, and toss to coat.

Whisk 2 tablespoons cornstarch and ¼ cup water together and pour over the skillet. Continue cooking and stirring until the sauce thickens.

Remove the pan from heat and serve fresh!