01 - Combine shredded chicken, mayonnaise, Greek yogurt, Dijon mustard, celery, red onion, dill, lemon juice, salt, and pepper in a medium mixing bowl. Mix thoroughly until all ingredients are evenly incorporated and the mixture is creamy and well blended.
02 - Wash and dry the cucumbers thoroughly. Using a mandoline slicer or vegetable peeler, slice cucumbers lengthwise into long, thin ribbons. Prepare approximately 16 even slices that are pliable enough for rolling without tearing.
03 - Place a cucumber ribbon flat on a clean work surface. Spread approximately 1 1/2 tablespoons of chicken salad mixture along one end of the ribbon. Add a few julienned carrots on top if using for extra texture and color.
04 - Gently roll the cucumber ribbon starting from the filled end, tucking in the filling securely as you roll. Place each completed roll seam side down on a serving platter to maintain its shape.
05 - Repeat the rolling process with remaining cucumber ribbons and chicken salad until all filling is used. Serve immediately for optimal crispness, or cover and refrigerate for up to 2 hours before serving. For best results, bring to room temperature for 10 minutes before serving if refrigerated.