Cook the pasta to al dente, according to package directions. Drain the pasta. Rinse with cold water to halt the cooking process. Drain well and set aside.

While the pasta is cooking, warm the oil in a large skillet over medium high heat. Brown the beef until cooked through, crumbling it as it browns. Drain thoroughly, then add the garlic and ginger and cook another minute or two until fragrant.

Whisk together the brown sugar, cornstarch, soy sauce, and chili paste. Pour the liquids over the beef, stir to combine, and bring to a simmer for 2 minutes to blend the flavors and slightly thicken the sauce.

Add peas, if desired. Stir, and simmer a minute longer. The peas will thaw and warm in the hot skillet. Add the cooked pasta to the skillet with the meat. Toss to mix well. Sprinkle with green onions before serving.