Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish.

Melt the butter in a large skillet over medium heat. Add the diced onion and chopped celery, cooking for about 5 minutes until soft. Add the minced garlic and cook for another minute, stirring constantly.

Sprinkle the flour over the vegetables and stir constantly for about 1 minute. Slowly whisk in the chicken broth, followed by the milk or cream, stirring constantly until the mixture is completely smooth with no lumps.

Add the cooked chicken and frozen peas and carrots to the skillet. Season generously with salt and black pepper. Let the mixture simmer for 5 to 7 minutes, stirring occasionally, until it thickens to a creamy consistency that coats the back of a spoon. Taste and adjust seasoning.

Pour the filling into your prepared baking dish and spread it out evenly.

Prepare the Red Lobster Cheddar Bay Biscuit Mix according to the package instructions.

Drop spoonfuls of biscuit dough evenly over the filling, leaving small gaps between each dollop. Bake uncovered for 25 to 27 minutes until the biscuits are golden brown on top and cooked through.

Remove from the oven and immediately brush the biscuits with the garlic butter packet included in the biscuit mix. Let cool for 5 minutes before serving.