Slice chicken breast, place in a small plastic zip baggie.
Whisk together cilantro, fish sauce, olive oil, soy sauce, lime juice, ginger, sugar substitute, and garlic. Pour over chicken, seal baggie, and chill for 1-3 hours.
Rinse and strain konjac noodles. Place in a dry nonstick pan, cook over medium heat for 5 minutes or so - stirring frequently - until most of the moisture has dried up. Remove from pan and set aside.
Chop cilantro and mint together, set aside.
Peel and seed cucumbers, cut into match sticks and set aside.
Rinse bean sprouts with cold water, allow to drain well. Set aside.
Saute chicken in olive oil until cooked through. Remove from heat and set aside.
Divide lettuce between bowls. Place a mound of cooled noodles on top of the lettuce.
Divide cilantro/mint mixture, cucumber, and bean sprouts among servings, arranging in sections on top of each. Top with jalapeno, if using.
Add cooked chicken to each bowl, sprinkle chopped peanuts over each serving, and serve with fish sauce.