Prep the cucumbers: Wash and dry.
Trim the ends, then slice lengthwise. Use a spoon to gently scoop out the seeds, creating a shallow “boat.” Pat the insides dry with a paper towel to reduce wateriness.
Season the boats: Lightly sprinkle the cucumber cavities with a pinch of salt and pepper. Set aside while you make the filling.
Mix the sauce base: In a bowl, stir together Greek yogurt, ranch dressing, lemon juice, and about half of the Buffalo sauce.
Taste and adjust heat and tang.
Add the chicken and crunch: Fold in shredded chicken, celery, and red onion. Mix until coated but not runny. If it looks dry, add a spoonful more Buffalo or a touch more yogurt.
Finish with cheese and herbs: Stir in blue cheese and chives.
Season with salt and pepper. The filling should be creamy, slightly thick, and spoonable.
Assemble: Spoon the mixture into the cucumber boats, mounding it slightly. Don’t overfill or it can spill when you pick them up.
Garnish: Drizzle with extra Buffalo or ranch, and sprinkle on more blue cheese or green onions if you like.
Serve: Enjoy immediately while the cucumbers are crisp and cold.