Season chicken breasts with Italian Seasoning.
Grill over high heat until meat is completely cooked through.
Cut meat in chunks and set aside.
Bring water to boiling in a large stock pot over high heat.
Boil pasta until al dente – about 11 minutes.
Drain in colander.
Set aside.
In a large Dutch oven, melt 4 tbsp. butter over medium heat.
Add whipping cream, half-and-half and parmesan cheese.
Stir frequently until cheese melts.
Add salt, pepper, garlic salt, thyme, oregano and chicken broth.
Cook over low to medium heat until mixture thickens—about 5-10 minutes.
Add chicken and stir to combine.
Place cooked pasta into the bottom of a 9x13” glass baking dish that’s been sprayed with cooking spray.
Pour sauce with chicken over top of the penne.
Sprinkle mozzarella cheese over top.
Combine remaining 2 tbsp. melted butter and panko bread crumbs.
Sprinkle over top of casserole.
Bake about 15 minutes at 350°.
If necessary, tent with foil to prevent noodles from browning too much.
Bake an additional 15-20 minutes or until bubbly and heated through.