Season the chicken breasts with Italian seasonings, garlic powder, salt, and pepper.
Heat a grill pan over medium heat and add a tablespoon of olive oil. Place the seasoned chicken breasts on the grill pan and cook for 4-5 minutes per side, or until the chicken is cooked through and has grill marks. Once done, remove the chicken breasts from the pan and set them aside on a plate.
Heat a large skillet over medium heat and add butter. Once the butter is melted, add minced garlic and cook for about a minute until fragrant.
Stir in whipping cream and milk, and let it cook for 2 minutes, allowing the mixture to heat through.
Add Parmesan cheese, Asiago cheese, salt, red chili flakes, and pepper to the skillet. Cook for a couple more minutes, stirring continuously until the sauce begins to slightly thicken. Once done, remove the skillet from the heat.
Meanwhile, cook the tortellini according to the package instructions. Drain the cooked tortellini and transfer it to a casserole dish.
Pour the prepared Alfredo sauce over the cooked tortellini in the casserole dish, ensuring the tortellini is evenly coated.
Arrange the grilled chicken breasts on top of the tortellini and sauce.
Place the casserole dish in the oven and set the broiler to high. Broil for 3-5 minutes, or until the dish is bubbly and lightly browned on top.
Once done, remove the casserole dish from the oven and garnish the Tortellini Alfredo with shavings of Parmesan cheese and fresh parsley.
Serve the Tortellini Alfredo with sliced grilled chicken on the side.