Combine chicken, soy sauce, ginger, and monk fruit together in a bowl. Refrigerate until ready to use.
Combine chicken stock, rice vinegar, garlic, tomato paste, soy sauce, sesame oil, monk fruit, and sriracha together in a bowl until well mixed.
Heat a large nonstick pan over medium high heat. When hot, add the chicken mixture. Cook, stirring often until chicken is no longer raw in appearance, about 5 minutes. Add half of the glaze and cook for another 10 minutes, until the mixture thickens and chicken begins to brown.
Reduce heat to medium, pour the rest of the glaze into chicken mixture, and cook until reduced a bit, about 5 minutes more. Allow to cool 5-10 minutes before serving.
While chicken cools, make the peanut sauce. Combine all ingredients except coconut milk. Heat coconut milk until barely simmering and then pour over the peanut butter mixture. Whisk until smooth and adjust seasoning to taste.
To assemble, spoon into lettuce leaves. Serve with fresh herbs, sliced radish, and peanut sauce on the side so people can add them to their taste.