Start by cooking the chicken in a pot over medium heat until it is browned and cooked through, approximately 15 minutes. The chicken should smell delicious as it sizzles. Be careful not to overcook it, so it does not dry out.
Next, melt 1 tablespoon of butter in the same pot, then toss in the diced onion and celery. Let them cook for about 5 minutes until they are soft and the onion becomes translucent, filling the kitchen with a savory fragrance. Avoid browning the vegetables for optimal flavor.
Stir in the minced garlic and cook for about 1 minute until fragrant. Pour in the diced tomatoes along with their juice. The aroma of the sauce will start to fill the air, enhancing the flavor profile.
Pour in the chicken broth and bring the mixture to a gentle boil, then add the penne pasta. Stir it well to prevent clumping, ensuring enough liquid is present to cook the pasta evenly.
Once the pasta is tender, lower the heat and mix in the buffalo sauce and cream cheese. Stir until everything is well combined and creamy; avoid having a grainy texture by adding the cream cheese over low heat.
Sprinkle in the cheddar and mozzarella cheese, stirring until they melt completely. The dish should be rich and oozy with cheese. Optionally, add a pinch of red pepper flakes for additional heat.
Taste the buffalo chicken pasta and adjust seasoning as needed. For extra creaminess, you may fold in the 2 tablespoons of cold butter. Serve warm.
Notes
Store leftovers in an airtight container in the refrigerator for 3-4 days. You can also freeze for up to 3 months.