In a wok, medium pot, or saucepan, heat the oil over medium heat. Whisking constantly, make a roux by adding the flour, turmeric, and paprika. Continue whisking for 15-20 seconds, then add the garlic and shallot.
Whisk for another 30 seconds. Next, whisk in 3 cups of the chicken stock. Bring the mixture to a simmer. Add the oyster sauce, light soy sauce, dark soy sauce, sesame oil, and white pepper to taste.
Combine the cornstarch with the remaining ¼ cup of chicken stock (or use water) to make a slurry. Slowly stir in two-thirds of the mixture.
Let the gravy cook and continue to thicken for 30 seconds. Add more of the cornstarch slurry if needed. The gravy should be thick enough to coat a spoon. Taste and adjust seasoning with additional salt or soy sauce according to your preferences. Serve!
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Notes
When reheating the gravy, you may need to add a little bit of water or chicken stock to thin it out, as it will solidify slightly. For more detailed information on the many ways to use cornstarch to get authentic results at home with our recipes, see our post on How to Use Cornstarch in Chinese Cooking.