01 - Combine shredded chicken, mayonnaise, Greek yogurt, Dijon mustard, diced celery, minced red onion, chopped dill, lemon juice, salt, and pepper in a medium mixing bowl. Mix thoroughly until all ingredients are evenly distributed and the mixture is creamy and well-blended.
02 - Wash and dry cucumbers thoroughly. Using a mandoline slicer or vegetable peeler, slice cucumbers lengthwise into long, thin ribbons approximately 1/8 inch thick. Prepare about 16 even slices for rolling.
03 - Lay a cucumber ribbon flat on a clean work surface. Spread approximately 1 1/2 tablespoons of chicken salad mixture along one short end of the ribbon. Add a few julienned carrot strips on top if using for extra crunch and color.
04 - Gently roll the cucumber ribbon from the filled end toward the opposite end, creating a tight cylinder that encloses the filling. Place each roll seam side down on a serving platter to maintain shape.
05 - Repeat the rolling process with remaining cucumber ribbons and chicken salad until all filling is used. Arrange finished rolls neatly on the serving platter.
06 - Serve immediately for optimal crispness, or cover and refrigerate for up to 2 hours before serving. Beyond 2 hours, cucumbers may become soggy from the filling moisture.