1. Combine first 4 ingredients in a small bowl; stir well.
2. Heat oil in a large nonstick skillet over medium-high heat. Add chicken; cook 5 minutes or until done, stirring to crumble. Add onions, and sauté 3 minutes. Add lime juice mixture, cilantro, and mint; sauté 2 minutes. Remove from heat; stir in peanuts.
3. Spoon 1/4 cup chicken mixture onto each lettuce leaf, and roll up.