Step 1: Cook the penne pasta according to package directions until al dente. Drain, reserving 1/2 cup of pasta water, and set aside.
Step 2: While pasta cooks, pat diced chicken dry with paper towels. Season chicken with salt, pepper, Italian seasoning, and paprika.
Step 3: In a large skillet or Dutch oven, melt 1 tbsp butter and 1 tbsp olive oil over medium-high heat. Add the seasoned chicken and cook for 5-7 minutes, stirring occasionally, until browned and cooked through. Remove chicken from the skillet and set aside.
Step 4: Reduce heat to medium. Add the remaining 1 tbsp butter to the skillet. Once melted, add minced garlic and sauté for 1 minute until fragrant. Do not brown.
Step 5: Pour in the chicken broth and heavy cream, scraping up any browned bits from the bottom of the pan. Bring the mixture to a gentle simmer, then reduce heat to low.
Step 6: Stir in the cheddar cheese and Parmesan cheese until melted and the sauce is smooth and creamy. If the sauce is too thick, add a splash of the reserved pasta water.
Step 7: Return the cooked chicken to the skillet with the sauce. Add the cooked penne pasta and toss to coat everything evenly. Taste and adjust seasoning as needed.
Step 8: Serve immediately, garnished with extra Parmesan cheese and fresh parsley, if desired.