In a medium mixing bowl, add your minced garlic, sugar, chili flakes, Sichuan pepper powder, Chinese five spice, and chicken stock powder. Keep them all together in the center of the bowl so the hot oil will hit them directly.
In a small saucepan or skillet, pour in the chili oil and neutral oil. Heat over medium until it is shimmering but not smoking. This usually takes about 1-2 minutes.
Carefully pour the hot oil over your dry seasoning mix. It will sizzle right away, releasing a deep aroma. Stir gently so the garlic does not burn, but the spices infuse fully.
Stir in soy sauce, rice vinegar, and hot water. Mix until everything blends into a rich sauce. If you are adding sesame paste or peanut butter, stir it now until smooth.
Bring a pot of water to boil. Cook your noodles according to package directions until it is just tender. Drain well.
While noodles are still hot, toss them directly in the spicy sauce. Mix until every strand is coated. Serve right away for the best taste.