Heat olive oil in a large skillet over medium-high heat.
Sauté onions and celery for 4 minutes until onions are translucent and celery is softened.
Add frozen peas, carrots, and cubed chicken to the skillet, stirring to combine.
Pour in chicken bone broth, thyme, garlic powder, salt, and pepper, then bring the mixture to a simmer.
Stir in the cornstarch slurry and continue to cook for 2 minutes until the sauce has thickened significantly.
Remove the skillet from heat and stir in the Greek yogurt until the sauce is creamy and well incorporated.
Serve immediately in shallow bowls.