Step 1

Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the pasta, and return to a boil. Cook uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 8 minutes. Drain well in a colander set in the sink.

Step 2

Preheat oven to 350 degrees F (175 degrees C). Grease a 2-quart casserole dish.

Step 3

Mix together the ham, sour cream, mushroom soup, 1/2 cup of mozzarella cheese, yellow mustard, and 1 tablespoon of parsley in a bowl until well combined. Fold in the cooked pasta, season to taste with salt and pepper, and spoon the mixture into the prepared casserole dish. Sprinkle top of casserole with 1/2 cup mozzarella cheese and 1 tablespoon of parsley.

Step 4

Bake in the preheated oven until the casserole is hot and bubbling, and the cheese topping has melted and begun to brown, about 30 minutes. Allow to stand 5 to 10 minutes before serving.