Preheat oven to 375°F.
Place a skillet over medium heat.
Add softened cream cheese to the skillet and allow it to warm.
Pour heavy cream into the skillet and stir until the cream cheese begins to melt.
Add grated parmesan and stir until the sauce becomes smooth and thickens slightly.
Add chopped sun-dried tomatoes into the skillet and stir to distribute.
Add cooked chopped chicken into the skillet.
Season chicken and sauce with salt and black pepper.
Stir until chicken is fully coated.
Transfer mixture into a small baking dish and spread evenly.
Sprinkle shredded mozzarella across the top.
Place baking dish uncovered into the oven.
Bake 15 to 18 minutes or until cheese melts and lightly browns.
Remove from oven and allow casserole to rest 3 to 5 minutes before serving.