In a large skillet or wok, heat the vegetable oil over medium heat. Add the diced onion and sauté until translucent, about 3-4 minutes.
Add the minced garlic and cook for an additional 1 minute until fragrant.
Stir in the shredded adobo meat and cook for 2-3 minutes until heated through.
Add the cooked rice to the skillet, breaking up any clumps. Pour in the soy sauce, vinegar, and sesame oil. Stir well to combine and heat the rice for about 5 minutes.
Push the rice mixture to one side of the skillet and pour the beaten egg into the empty side. Scramble the egg until fully cooked, then mix it into the rice.
Stir in the sliced green onions and season with salt and pepper to taste. Cook for an additional 1-2 minutes.
Remove from heat and serve hot.