In a large pot, bring water to a boil to cook the noodles according to the directions on the box (enough water to cover noodles, boil for approximately 5 minutes).
While the pasta cooks, mince the garlic and chop the green onions. Melt the butter in a large skillet over medium heat. Once the butter is melted and bubbly, add the garlic and onions and saute until they are soft but not browned.
While the pasta, garlic and onions are cooking, mix the oyster sauce, brown sugar, soy sauce and sesame oil together in a bowl.
Once the pasta is done cooking, drain it in a colander. Remove the skillet with the sauteed garlic and green onions from the heat. Add the drained pasta and oyster sauce mixture to the skillet and stir well to coat the pasta. If your pasta is stiff or sticky making it hard to stir, mix in a small amount (1/4 cup or less) of hot water to loosen them up.