Set a large pan over medium high heat. Add oil and noodles. Spread noodles into an even layer and cook until browned. Flip the cake noodle and repeat the cooking process on the other side. Remove from pan and set aside.
Add butter to another pan set over medium high heat. When butter has melted add shrimp and garlic salt. Toss to combine. Cook until shrimp is no longer translucent and pink or about 2-3 minutes on each side. Remove from pan and set aside.
Add oil to the pan along with mushrooms, bok choy, zucchini, carrots, and onions. Stir fry until just softened. Be sure not to over cook veggies.
While veggies are cooking begin the sauce. To a pot over medium high heat add chicken stock, oyster sauce, shoyu, sugar, sesame oil, salt, and pepper. Whisk until well combined.
Mix cornstarch and water then add to sauce to thicken.
Place veggies back on the heat. Add shrimp to pan along with the sauce. Toss until well combined.