1. 1. Prepare the Chicken Mixture: In a medium bowl, combine the shredded or diced cooked chicken with the buffalo sauce, Greek yogurt (or mayonnaise), finely chopped celery, and red onion (if using). Stir everything together thoroughly until the chicken is evenly coated. The mixture should be moist but not overly saucy.

2. 2. Warm the Tortillas (Optional): If your tortillas are stiff or you prefer them softer, briefly warm them in the microwave for 10-15 seconds each, or in a dry skillet over medium heat for about 30 seconds per side. This makes them more pliable and easier to roll without tearing.

3. 3. Assemble the First Wrap: Lay one warmed tortilla flat on a clean surface. Spoon about a quarter of the buffalo chicken mixture down the center of the tortilla, leaving a border around the edges.

4. 4. Add the Veggies: Layer about a quarter of the shredded lettuce and shredded carrots over the chicken mixture. If using, sprinkle some crumbled blue cheese over the vegetables.

5. 5. Fold the Sides: Fold in the two opposite sides of the tortilla over the filling, just enough to cover the edges of the chicken mixture. This helps to contain the filling when you roll it.

6. 6. Roll It Up Tightly: Starting from one of the unfolded ends, tightly roll the tortilla upwards, tucking in the filling as you go. Roll it as snugly as possible to prevent it from falling apart.

7. 7. Repeat for Remaining Wraps: Continue this process with the remaining tortillas and filling until all four wraps are assembled.

8. 8. Serve or Pack: You can serve the wraps immediately, perhaps with a side of ranch or blue cheese dressing for dipping, or wrap them tightly in plastic wrap or parchment paper for a cold packed lunch.