Preheat your oven to 375°F (190°C) and grease a casserole or pie dish lightly.

In a large mixing bowl, combine the cooked chicken, frozen mixed vegetables, cream of chicken soup, garlic powder, onion powder, salt, pepper, and chicken broth. Stir until fully incorporated.

Pour the filling mixture into your prepared dish, spreading it evenly.

In a separate bowl, whisk together the all-purpose flour, baking powder, and a pinch of salt. Cut in the cold butter until it resembles coarse crumbs. Fold in the cheddar cheese and garlic powder, then add the milk until just combined.

Drop spoonfuls of biscuit dough over the filling, covering most but not all to allow steam to escape.

Bake in the preheated oven for about 30 minutes, until biscuits are golden brown and filling is bubbling.

Allow to cool for a few minutes before serving warm.