In a bowl, toss the thinly sliced beef with salt, pepper, and a tablespoon of soy sauce. Let it marinate for about 15 minutes for extra flavor.
Heat a large skillet or wok over medium-high heat and add 1 tablespoon of vegetable oil. Once hot, add the marinated beef in a single layer. Sear the beef for about 2-3 minutes until crispy and browned, then remove it from the skillet and set aside.
In the same skillet, add another tablespoon of vegetable oil. Add the minced garlic and sauté for about 30 seconds until fragrant. Then add the diced bell pepper and carrot. Stir-fry for about 3-4 minutes until the vegetables are tender but still have a bit of crunch.
Add the cooked rice to the skillet with the vegetables, breaking up any clumps. Pour in the remaining soy sauce, oyster sauce (if using), chili paste, and sesame oil. Toss everything together until the rice is evenly coated in the sauces.
Return the crispy beef to the skillet and mix well with the rice and vegetables. Stir-fry for an additional 2-3 minutes to allow the flavors to meld.
Take the skillet off the heat and fold in the chopped green onions.
Transfer the crispy chili beef fried rice to plates or bowls.
Notes
Garnish with fresh cilantro and additional green onions for presentation.