Final answer:
A Protein Style Burger usually substitutes burger buns with lettuce and includes a beef patty, cheese, and various toppings. Gluten-free buns are an option, and extras like bacon and caramelized onions can be added.
Step-by-step explanation:
The key ingredients of a Protein Style Burger typically include lettuce used in place of traditional burger buns, a beef patty, cheese such as Swiss or yellow cheddar, mayonnaise, tomato, sauces like ketchup or ranch, onions, relish, and pickles. Gluten-free buns may also be available as an alternative. For additional protein and flavor, one can add bacon strips, and to cater to personal taste preferences, mushrooms, caramelized onions, or special sauces can be included as well.