What is a common side dish that customers can order with their meals at Carl's Jr.?

The common side dish that customers can regularly order with their meals at Carl's Jr. is indeed French fries. This option is a staple offering at fast-food restaurants and is widely recognized as a classic accompaniment to burgers and sandwiches. French fries are typically fried until golden brown, offering a crispy texture that complements the savory flavors of the main items on the menu.

While onion rings, salad, and fruit cups are also available at Carl's Jr., they are not as universally ordered as French fries. Onion rings provide a different texture and taste and may not appeal to every customer compared to the familiar flavor of fries. Salads and fruit cups cater to those seeking healthier options, but again, they do not have the same level of popularity and historical association with fast-food meals as fries do. Thus, French fries reign as the quintessential side dish that many customers expect to find alongside their meals at Carl's Jr.