Which ingredient is commonly added to Jersey Mike's sandwiches for extra flavor?

Provolone cheese is a well-known ingredient at Jersey Mike's, often utilized to enhance the flavor profile of their sandwiches. This cheese is prized for its mild, slightly tangy taste that complements a variety of meats and toppings. Provolone's creamy texture melts beautifully, which adds richness to the sandwiches, making it a popular choice for enhancing taste.

The other options, while they can provide flavor, are not as signature to Jersey Mike's offerings. Avocado and pineapple can be used for specific sandwiches but are not as commonly associated with their menu. Red onions contribute a sharpness that can enhance certain flavors, but provolone cheese stands out as a fundamental ingredient used frequently to elevate the overall taste experience in many of their sandwiches.