Cook the chicken.
Preheat the oven to 400 F. Spray a 9 x 13 pan with non stick spray and set off to the side.
Melt 4 Tablespoons of butter in a large skillet over medium heat. Add the garlic and onions and cook for 3 to 5 minutes, until soft. Mix in the flour and cook for 1 to 2 mins then add in the chicken broth and whisk.
Next, add in the milk and Stir constantly while mixing in milk and bring it up to a soft boil(just until it starts to bubble).
Keep stirring for 3 minutes while the mixture gently bubbles and thickens.
Once bubbly and has thickened add in the shredded chicken, vegetables, and seasonings.
Melt butter in the microwave in a microwave safe bowl for 30-45 seconds until all of the butter is melted.
Pour in melted butter and mix thoroughly with a fork, breaking up as many clumps as you can.
Then, add milk and mix thoroughly with a fork, breaking up as many clumps as you can.
Stir in the shredded cheddar cheese.
When the filling is done cooking remove it from the oven and work quickly use the fork to drop the biscuit mix in ping pong ball size lumps on top of chicken mixture, do NOT mix in.
Return the dish to the oven for 15 to 18 minutes until the biscuits are golden brown.