Cook the penne pasta according to package directions until al dente, then drain.
In a large skillet, cook the chicken over medium heat until golden brown and cooked through, about 6-8 minutes per side.
Once the chicken is cooked, remove it from the skillet and let it rest before dicing into bite-sized pieces.
In the same skillet, add chicken broth and ranch seasoning, stirring to combine.
Stir in the cream cheese, allowing it to melt completely into the broth mixture.
Add the shredded cheddar cheese, mixing until melted and creamy.
Return the diced chicken to the skillet, combining it well with the creamy sauce.
Fold in the cooked penne pasta, mixing until the pasta is evenly coated.
Taste and season with salt and pepper as needed. Serve warm, garnished with chopped green onions if desired.