Use a mortar and pestle to mash the spring onion, ginger, and salt into a rough paste. Next heat vegetable oil and sesame oil in a small saucepan over medium-high heat and pour it over the spring onion mixture. Stir and set aside.
Cook the pasta in salted boiling water until al dente. Make sure to save 1 cup of pasta water.
Heat 1 tablespoon of vegetable oil in a pan over medium heat. Add garlic, shrimp, and chili flakes. Cook for 2-3 minutes until the shrimp turn pink. Stir in soy sauce and oyster sauce, simmer briefly, then turn off the heat.
Drain pasta and add it to the pan. Turn heat to high and toss for 2-3 minutes until the sauce thickens. Add pasta water if needed.
Stir in the spring onion sauce, mix well, and serve!