Bring a large pot of salted water to a boil. Add the spaghetti and cook until al dente, typically 8-10 minutes. Reserve 1/4 cup of pasta water, then drain.

In a skillet, heat 1 tablespoon of neutral oil over medium-high heat. Add the ground beef, breaking it up, and cook for 5-7 minutes until browned.

Lower the heat, add minced garlic and grated ginger, and sauté for about 1 minute.

Stir in soy sauce, chili oil, brown sugar, and rice vinegar. Simmer for 2-3 minutes.

Add drained spaghetti to the skillet and toss until fully coated. Adjust the consistency with reserved pasta water if necessary.

Drizzle with sesame oil, top with green onions and sesame seeds, and serve immediately.