Final answer:
The egg whites on the surface of a meringue are cooked when broiling or torching, as they undergo caramelization of the sugars, leading to a browned top while the inside remains soft.
Step-by-step explanation:
When broiling or torching a meringue, the egg whites on the surface are what undergo the cooking process. The intense heat from the broiling or torching caramelizes the sugars within the egg whites, creating a delicious crispy and browned top layer while the interior remains soft and fluffy. This is a chemical reaction between the amino acids from the egg whites and the sugar, known as the Maillard reaction, which imparts the meringue with its characteristic color and flavor. This is why it's important to use just the right amount of heat to cook the meringue to achieve the perfect texture and taste.