In a large skillet cook garlic and onions until onions are translucent.
Add the flour and 2 tbsp. Chicken broth and stir until onions are well coated.
Slowly add the milk and broth and stir to combine.
Season well with salt and pepper, stir everything together and simmer until the sauce thickens. The consistency should be similar to a potato soup.
Transfer the chicken, vegetables and sauce mixture to the prepared casserole dish.
Stir to evenly tix everything together and spread along the bottom of the dish.
Unroll your crescent rolls and place along the top of the chicken mixture.
Bake for 20 minutes until the top is golden brown and cooked through. Remove from the oven and serve.