A McChicken is a kind of sandwich that you can buy at McDonald's. It's made with a crispy, breaded chicken patty, which means the chicken is coated in breadcrumbs and fried until it's crunchy on the outside and juicy on the inside. The patty is placed on a soft, sesame seed bun with lettuce and mayonnaise. The lettuce is kind of like crunchy leaves that people like to eat in salads and the mayonnaise is a creamy sauce made from eggs and oil. When you take a bite, it's crispy, crunchy, and delicious!