Preheat the oven to 350°F.

Melt the butter in a large pot over medium heat. Add the chopped onion, celery, and carrot and sauté for about 5 minutes, until softened.

Add the minced garlic and cook for another minute.

Sprinkle the flour over the vegetables and stir, cooking for 1 minute. Add the celery salt, onion powder, garlic powder, and rosemary; stir to combine.

Slowly pour in the chicken stock and milk while stirring, letting the mixture gradually thicken over a few minutes.

Stir in the heavy cream, peas, shredded chicken, and whole grain mustard. Turn off the heat.

While the filling sits, boil the gnocchi until they float to the top of the pot. Drain well, making sure there’s no excess water.

Assemble the pot pie in a small baking dish (mine is 8.5 x 6.5 inches): spoon the filling into the dish first, then scatter the cooked gnocchi over top. Drizzle lightly with olive oil and finish with the grated parmesan.

Bake for 25 minutes, then broil for 1–2 minutes if you’d like the top extra golden.