Toast the Chinese sausage in a skillet over medium heat until cooked through. Remove and set aside.

In the same skillet, add vegetable oil. Sauté the minced garlic until fragrant, then add the diced onion and carrot. Stir-fry until slightly softened.

Add the egg and scramble until just set. Add the cooked rice and stir-fry to combine. Season with oyster sauce, fish sauce, soy sauce, black pepper, and sugar. Stir-fry over high heat until everything is well mixed.

Add the cooked Chinese sausage and sliced green onion. Stir-fry briefly to combine.