Step 1

Arrange a rack in the middle of the oven and heat to 425°F. Coat a 2-quart baking dish with butter; set aside.

Step 2

Whisk the flour, parsley, baking soda, and salt together in a medium bowl. Add the cream and use a wooden spoon to stir until a shaggy dough forms. Refrigerate while you prepare the casserole.

Step 3

Melt the butter in a Dutch oven or large pot over medium heat. Add the flour and whisk until completely combined. The mixture will look like wet sand. Cook until the mixture begins to dry out and turn golden-brown, about 4 minutes.

Step 4

Gradually whisk in a little bit of the milk until smooth, then whisk in the remainder. Whisk in the chicken broth until smooth. Bring to a boil, then reduce the heat and simmer, stirring constantly, until thickened, 5 to 8 minutes.

Step 5

Remove from the heat and stir in the chicken, vegetables, parsley, chives, salt, and pepper. Transfer to the prepared baking dish and spread into an even layer.

Step 6

Scoop out about 2 tablespoons of biscuit dough, use your hands to shape it into a 1/2-inch-thick patty, and place on top of the casserole. Repeat with the remainder of the dough, spacing the biscuits about 1/2 inch apart.

Step 7

Bake until heated through and bubbling and the biscuits are golden-brown, 15 to 18 minutes. Let cool about 5 minutes before serving.