Season the diced chicken breasts with salt and pepper. Heat vegetable oil in a large skillet or wok over medium-high heat. Add the chicken and cook for 5-7 minutes until browned and cooked through. Remove and set aside.
In the same skillet, add minced garlic and ginger. Sauté for 30 seconds until fragrant. Add frozen peas and carrots, stir-fry for 2-3 minutes until heated through.
Push the vegetables to one side of the skillet. Pour the beaten egg into the empty side and scramble until fully cooked. Mix with the vegetables.
Add the cooked rice and chicken back into the skillet. Pour in soy sauce, sweet chili sauce, and sesame oil. Stir until well combined and heated through, about 3-5 minutes.
Remove from heat and stir in chopped green onions. Adjust seasoning with salt and pepper if needed. Serve hot.