Combine dried oregano, paprika, garlic powder, kosher salt, black pepper, onion powder, and cayenne in a small mixing bowl. Mix well and set aside.
Prepare the Chicken
Butterfly two chicken breasts into four thin cutlets. Season them with the blackening spice making sure the chicken is well coated.
Sauté the Chicken
Add avocado oil to a nonstick skillet over medium high heat. Once the oil is hot, add the blackened chicken. Sauté the chicken on both sides for 5-6 minutes or until it is cooked through. The internal temperature should reach 165 degrees Fahrenheit to ensure doneness. Remove the chicken from the pan with tongs and place it on a plate.
Make the Sauce
Reduce the heat to medium and in the same pan, add the butter. Once it begins to melt, add the diced onion and saute. Next, add the minced garlic. Sauté until the onion begin to soften. Deglaze the pan with low sodium chicken broth. Be sure to scrape any bits from the bottom of the pan. Let the broth reduce by half, then add the heavy cream and Dijon mustard. Mix well. Add the grated parmesan cheese and stir until it is well combined and melted.
Assemble
Once the sauce is well combined, nestle the chicken and its juices back into the pan with the sauce. Taste and season with kosher salt and cracked black pepper as needed.
Notes
Storage
Store any leftover chicken and sauce in an airtight container in the refrigerator for three to four days.
Reheat leftovers in a nonstick pan or in the microwave. Add a touch of water or broth to the pan or the microwavable bowl. This will help reconstitute the sauce, making it smooth and creamy again.