Add vegetable oil to a pan over medium heat
While oil is heating, whisk together soy sauce, oyster sauce, white sugar, brown sugar, and fish sauce in a bowl until well combined or until sugar has dissolved.
When the oil is glistening + hot, add the shallots and garlic to pan and cook until fragrant, 3-5 minutes.
Add chicken to pan and cook about 5 minutes or until it loses its color.
Once chicken has lost its color, drain any excess liquid. Add the thai chilis and sauce. Increase heat to medium high and cook until sauce reduces to a glaze and coats chicken, about 3-5 more minutes. Stir frequently.
Add in basil and stir for another 30 seconds to one minute, or until basil is wilted.
Salt and Pepper to taste. Serve immediately over cooked rice and garnish with extra basil if desired!