What is the preferred cooking method for delicate proteins like fish?

Poaching is the preferred cooking method for delicate proteins like fish because it involves cooking in simmering liquid at a low temperature, which helps to maintain the moisture and tenderness of the fish. This gentle cooking process prevents the proteins from becoming tough or dry, preserving their delicate texture and ensuring that they remain flavorful.

In contrast, grilling and frying expose fish to higher temperatures which can lead to overcooking and loss of moisture, making the fish tough and less palatable. Baking, while a suitable method for cooking fish, often involves higher heat and extended cooking times which may not be ideal for the delicate nature of fish. Thus, poaching stands out as the best method for achieving perfectly cooked, tender fish.