Dice shitake mushrooms into small pieces and cook them with 1/2 tbsp soy sauce and 1/2 tsp 5-spice powder until fully cooked on a pan.
To a bowl, add gochugaru, 5-spice powder and sichuan pepper.
Heat up sesame oil but make sure the oil doesn't burn. Pour this hot oil over the dry spices.
Add light and dark soy sauce, veg oyster sauce, agave syrup and cooked shitake mushrooms. Give the sauce a good mix.
Cook knife shaved noodles according to package instructions. Drain noodles and keep the starchy noodle water.
Add noodles into the sauce and 1/4 cup noodle water. Toss and combine until the sauce coats all the noodles.
Garnish with toasted sesame seeds, chili oil and scallions. Enjoy!