Which of the following dishes contains sulphites?

Crispy yam fries are the correct choice as they often contain sulphites, which are used as preservatives to maintain color and freshness. These compounds are commonly found in various food items, especially processed ones or those that have gone through drying or preservation processes.

Yam fries, when prepared commercially or even sometimes homemade, may be treated with sulphites to prevent browning and spoilage, making them appealing and extending their shelf life. Understanding the role of sulphites is important, particularly for individuals who may have sensitivities or allergies to these additives.

On the other hand, the other dishes listed—mini burgers, Szechuan lettuce wraps, and calamari—typically do not contain sulphites as a standard ingredient. While it's always possible for any dish to be prepared in a way that introduces sulphites, crispy yam fries are notably associated with them due to their common processing methods.