1. In a small bowl, combine soy sauce, fish sauce, brown sugar, mirin, and cornstarch and mix together.
2. In a sauté pan or wok, heat with oil and stir fry the beef for about 3 minutes.
3. Add garlic, shallots, chilies, and bell peppers and cook until meat and peppers are tender.
4. Pour the soy sauce mixture into the pan and coat the beef and vegetables. The sauce will start to thicken.
5. Turn off the heat and toss in the Thai basil leaves and finish off with cracked pepper. Serve over rice.