1. Preheat oven to 400°F.
2. In a medium sauce pan over medium high heat, cook bacon until crisp. Drain bacon and remove and place on a paper towel to drain. Leave bacon drippings in the pan.
3. Meanwhile evenly lay pierogies in a baking dish.
4. Add butter and flour. Whisk to combine. Cook for about 3 minutes to cook out the flour-y taste. Add chicken broth, half & half, garlic, onion, Italian seasoning, cayenne, and pepper. Whisk until combined. Add Italian cheese and about half of Parmesan cheese. Stir to combine. Add frozen peas and chicken. Stir to combine. Bring to a bubble, about 3 minutes.
5. Pour chicken and cheese mixture over pierogies. Sprinkle remaining parmesan cheese over top.
6. Bake for 15 minutes until top is bubbly and golden brown.
7. Remove from oven sprinkle with bacon and parsley. Serve and enjoy!