Cook the Pasta:

• Bring a large pot of salted water to a boil.
• Add the penne pasta and cook according to package instructions until al dente.
• Reserve 1/2 cup of the pasta cooking water, then drain the pasta and set aside.

Cook the Bacon:

• In a large skillet over medium heat, cook the chopped bacon until crispy, about 8-10 minutes.
• Use a slotted spoon to transfer the bacon to a paper towel-lined plate to drain.
• Reserve 2 tablespoons of the bacon grease in the skillet, discarding any excess.

Cook the Chicken:

• Season the chicken pieces with a pinch of salt and pepper.
• In the same skillet with the reserved bacon grease, add the chicken and cook over medium heat until browned and cooked through, about 6-8 minutes.
• Remove the chicken from the skillet and set aside.

Prepare the Sauce:

• In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant.
• Sprinkle the flour over the garlic and whisk to combine, cooking for about 1 minute to form a roux.
• Gradually whisk in the heavy cream and milk, stirring constantly to prevent lumps.
• Bring the mixture to a gentle simmer, allowing it to thicken slightly, about 2-3 minutes.
• Stir in the ranch seasoning mix until fully incorporated.

Combine Ingredients:

• Reduce the heat to low and add the shredded cheddar and Parmesan cheeses to the sauce, stirring until melted and smooth.
• If the sauce is too thick, add a bit of the reserved pasta water to reach the desired consistency.
• Add the cooked pasta, chicken, and half of the cooked bacon to the skillet, stirring to combine and heat through.

Serve:

• Taste and adjust seasoning with salt and freshly ground black pepper as needed.
• Serve the pasta warm, garnished with the remaining bacon and chopped parsley or chives.