Begin cooking the penne noodles according to the directions on the box. While the noodles is cooking, begin preparing the alfredo sauce.
In a saucepan, melt the butter over medium heat. Fry the garlic in the butter for 60 seconds then add in the cream. Whisk for five minutes constantly. Pour in the parmesan cheese and stir until melted. Salt and pepper to taste.
Drain the noodles and transfer to a baking dish. Pour the alfredo sauce over the noodles, add in the cooked chicken, and add in the cooked peas. Stir to combine.
You can either eat it as it is now, or you can throw in the oven to bake for 10 minutes.