Bring a large pot of salted water to a boil. Add the dry spaghetti noodles and cook according to the package directions until just al dente. Reserve about 1/2 cup of the starchy pasta water, then drain the noodles and set them aside.

While the noodles cook, heat the neutral cooking oil in a large skillet or wide pan over medium-high heat.

Add the lean ground beef to the hot skillet. Cook, breaking it up with a spatula, until the beef is browned and no longer pink, about 5–7 minutes. If there is excess grease, carefully spoon off some, leaving a thin layer in the pan for flavor.

Add the minced garlic and grated fresh ginger to the browned beef. Cook, stirring constantly, for 30–60 seconds until fragrant, being careful not to let the garlic burn.

Reduce the heat to medium. Pour in the low-sodium soy sauce, brown sugar, rice vinegar, toasted sesame oil, crushed red pepper flakes, and low-sodium beef broth. Stir well to combine, scraping up any browned bits from the bottom of the pan.

Add the shredded carrots to the skillet and stir them into the saucy beef mixture. Let the mixture simmer gently for 3–4 minutes to slightly soften the carrots and allow the flavors to meld.

Add the cooked spaghetti noodles to the skillet with the beef and sauce. Using tongs, toss the noodles thoroughly so they are evenly coated. If the mixture looks too dry or the noodles are sticking, splash in a little of the reserved pasta water, a tablespoon at a time, until the sauce clings smoothly.

Sprinkle in the black pepper and half of the sliced green onions. Toss again to distribute the aromatics evenly through the noodles and beef.

Taste the noodles and adjust the seasoning if needed by adding a small splash of soy sauce for more saltiness or a pinch more crushed red pepper flakes for extra heat.

Divide the Korean ground beef and noodles among serving bowls. Top each portion with the remaining sliced green onions and a generous sprinkle of toasted sesame seeds. Serve hot and enjoy.