Begin by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add your spaghetti, stirring occasionally, and cook it according to the package instructions until al dente, usually around 8-10 minutes. After cooking, reserve 1/4 cup of the pasta water for later, then drain the spaghetti and set it aside to keep warm.

In a large skillet, heat a tablespoon of neutral oil over medium-high heat. Once hot, add the ground beef, breaking it apart with a spatula while it cooks, ensuring it browns evenly. Cook for about 5-7 minutes until it's fully browned and no longer pink, draining any excess fat if necessary.

Reduce the heat to medium, and toss in the minced garlic and grated ginger to the skillet. Sauté for about 1 minute, stirring constantly until fragrant and golden.

Next, stir in the soy sauce, chili oil, brown sugar, and rice vinegar into the skillet. Allow the mixture to simmer for 2-3 minutes, stirring occasionally until it thickens slightly.

Gently fold the drained spaghetti into the sauce mixture in the skillet. Toss well, ensuring every strand of noodle is coated in the flavorful sauce.

Remove the skillet from heat and drizzle the sesame oil over the spaghetti, giving it a final toss. Sprinkle the chopped green onions and optional sesame seeds on top for crunch and color.