Gather the ingredients. Preheat the oven to 375°F. Place butter in the bottom of a 9x13 baking dish and place in the oven to melt.
STEP 2
When butter is melted, add chicken in a single layer over the butter. Top evenly with frozen veggies.
STEP 3
Stir together biscuit mix, seasoning packet, and milk in a bowl until well blended; pour over the chicken and veggies. Spread lightly and evenly over the mixture but do not stir.
STEP 4
Whisk together soup and stock in a second bowl until smooth. Pour over biscuit mix but do not stir.
STEP 5
Bake in the preheated oven uncovered until very golden brown and slightly jiggly in the center, about 45 minutes.
STEP 6
Sprinkle parsley over the top if desired and let stand for 10 minutes before serving.