Finely dice the celery and red onion into uniform pieces so every forkful stays balanced and crisp.

In a small bowl, whisk together the Greek yogurt, olive oil, Dijon mustard, garlic powder, kosher salt, black pepper, and crushed red pepper flakes until smooth and lightly thickened.

Add the shredded chicken, celery, red onion, and cilantro to the bowl with the avocado.

Pour the dressing over the salad and fold gently from the bottom upward using a spatula. Keep some avocado pieces intact so the final texture stays creamy without becoming mashed.

Taste and adjust seasoning with an extra pinch of salt if needed. The chicken absorbs seasoning quickly, so proper salting is important.

Sprinkle the toasted pumpkin seeds and flaky sea salt over the top just before serving for contrast and crunch.

Serve chilled in lettuce cups, croissants, toasted sourdough, or over mixed greens.