Preheat the oven to 375 degrees.
In a large pan, cook the onions in the olive oil over medium-low heat for 3 minutes.
Add the potatoes and cook for 8 minutes, until they begin to soften.
Add the carrots and celery and cook for another 5 minutes.
Stir in the flour and add the chicken broth gradually. Add the diced chicken, salt, and pepper to the mixture.
Simmer gently for 10 minutes, stirring regularly to thicken.
While the mixture simmers, make the biscuit batter. Mix together the dry ingredients and the butter in a food processor until it reaches a crumb-like consistency. In a large bowl, stir together the crumb mixture with the yogurt to form the biscuit dough. Set aside.
Transfer the chicken and vegetable mixture to a 9 by 13 inch pan. Form 10 patties out of the biscuit dough and divide them across the top of the chicken mixture.
Bake for 25 to 30 minutes, until the biscuits are cooked through.