Easy fried rice recipe

Ingredients: 2 cups cooked rice (preferably day-old) 2 tablespoons vegetable oil 2 eggs, beaten 1 small onion, finely chopped 1 cup mixed vegetables (peas, carrots, corn, etc.) 2-3 tablespoons soy sauce (adjust to taste) 1 tablespoon oyster sauce (optional) 2 green onions, sliced Salt and freshly ground black pepper, to taste Optional: cooked chicken, shrimp, or tofu