I made this with shrimp instead of chicken
Doubling this pasta dish requires doubling the pot capacity to at least six quarts to maintain vigorous boiling action for the penne without dropping the water temperature below the gelatinization threshold for the starch. When multiplying dairy-heavy sauces containing half-and-half and shredded asiago cheese, scale the volume linearly while monitoring the reduction rate carefully because wider pans evaporate moisture faster than deep skillets. Maintaining the correct ratio of pasta water to cream sauce ensures the starches bind properly without separating the fats.
Testing poultry doneness without a probe thermometer relies entirely on visual and textural cues rather than guesswork. Slicing the thickest portion of the chicken breast open should reveal completely opaque white flesh with zero translucent pink remaining in the center, and the juices must run totally clear when pressed with the flat side of a chef knife. Overcooking causes the protein fibers to contract tightly and squeeze out moisture, resulting in a rubbery texture against the tender penne and soft spinach leaves.