01 -  Preheat oven to 375°F. Lightly grease a standard 12-cup muffin tin. 
 02 -  Melt unsalted butter in a large skillet over medium heat. Add finely diced onion and cook until translucent, roughly 3 minutes. 
 03 -  Sprinkle all-purpose flour over sautéed onions, stir thoroughly, and cook for 1 minute to remove raw flavor. 
 04 -  Gradually whisk in chicken broth and ranch dressing until smooth. Continue stirring until mixture gently thickens, about 2 to 3 minutes. 
 05 -  Stir in Cajun seasoning, garlic powder, black pepper, frozen mixed vegetables, and diced chicken breast. Cook until vegetables are heated through, approximately 2 to 3 minutes. Remove skillet from heat. 
 06 -  Flatten each biscuit dough round and press gently into the bottom and along the sides of the muffin tin cavities to form cup shapes. 
 07 -  Distribute chicken and vegetable filling evenly among the prepared biscuit cups. Sprinkle each with shredded cheddar cheese if desired. 
 08 -  Place muffin tin in oven and bake for 18 to 22 minutes, until biscuits are golden brown and the filling is bubbling. 
 09 -  Allow baked pot pie cups to cool for 5 minutes before removing from tin. Serve warm.