Preheat oven to 375 degrees F.
Heat griddle on medium low to medium. While griddle is heating up, pound out chicken breasts so that each breast is uniform in thickness. Then, season both sides of each piece of chicken with your blackening seasoning (or substitute all-purpose seasoning of your choice).
Place a large skillet on the heated griddle surface and allow it to warm up. Add a separate pot of hot water to the griddle to boil (to cook the tortellini later). To the skillet, add one stick of butter and the minced garlic. Allow the butter to melt and the garlic to become fragrant.
In a small bowl, add the panko breadcrumbs and dried parsley. Take about 3 tablespoons of the melted butter and garlic from the skillet and pour over top of the panko. Stir to combine. Set the panko breadcrumb "topping" to the side.
Add the pint of heavy cream and the cup of half and half to the butter and garlic in the skillet. Stir to combine and allow the cream to warm. Then, add the 10 oz. of freshly grated parmesan cheese. Stir occasionally as the cheese melts into the cream and the Alfredo sauce thickens. *Do not allow the sauce to get too hot. Continue to cook the Alfredo sauce, stirring occasionally. Add salt and pepper to taste.
While the Alfredo sauce continues to cook, add about 1-2 tablespoons of your favorite cooking oil to the heated griddle surface, and use your spatula to spread it around in a thin even layer. Place the seasoned chicken breasts on the oiled griddle surface. Cook chicken on the first side until about half-way cooked through. Then, flip the chicken to the second side and continue to cook until each breast reaches an internal temp of 165 degrees F. *Temp each piece of chicken individually, and remove the chicken from the griddle as it reaches the proper internal temp. Allow the cooked chicken breasts to rest on a cutting board.
While the chicken is resting, add the packaged tortellini to the pot of boiling water. Cook the tortellini according to package instructions. Then, turn the griddle off, drain the pasta, and transfer pasta to the warm griddle in a thin layer for about 1-2 minutes. This allows the pasta to dry out a bit.
Butter a 10" cast iron skillet or other baking dish.
Cut the cooked chicken into bite-sized pieces. Add the chicken, tortellini, about 2 oz of grated parmesan cheese, and about 3/4 of the Alfredo sauce to a large bowl and stir to combine. Spread the blackened chicken Alfredo pasta in the prepared cast iron skillet or baking dish. Spoon the rest of the Alfredo sauce over top. Sprinkle the panko crumb topping on top of the pasta. Bake in the preheated oven for about 20 minutes, or until the crumb topping is lightly golden brown and the dish is bubbly.
Remove Alfredo pasta bake from the oven, and allow to cool for about 5-10 minutes before serving.