Prep the dressing: In a medium bowl, whisk the Greek yogurt, Dijon, lemon juice, a pinch of salt, and black pepper.
Taste and adjust acidity with more lemon if needed.
Fold in flavor: Add the celery, red onion, cucumber, dill, and parsley. Stir until coated and evenly distributed.
Add the chicken: Mix in the shredded or diced chicken until everything is well combined. If using feta, gently fold it in now.
Chill (optional but recommended): Let the mixture sit in the fridge for 10–20 minutes.
This helps the flavors meld and slightly thickens the dressing.
Warm the tortillas: Briefly heat each tortilla in a dry skillet for 10–15 seconds per side to make them flexible and less likely to tear.
Assemble the wrap: Lay down a handful of greens on the tortilla. Spoon 1/2 to 3/4 cup of chicken salad on top. Add tomato or bell pepper if using.
Wrap it up: Fold the sides in, then roll tightly from the bottom up.
Slice in half if you like.
Serve: Enjoy right away, or wrap in parchment or foil for later.