Mix the Ingredients: In a large mixing bowl, gently combine the ground chicken, breadcrumbs, diced red, yellow, and green peppers, minced chipotle peppers, adobo sauce, garlic, cilantro, salt, and black pepper. Be careful not to over-mix, which can make the chicken tough.
Form the Patties: Divide the mixture into 4 equal portions and shape them into patties. Ground chicken can be sticky, so rub your hands with a drop of cooking oil to make handling easier.
Cook: Heat a cast-iron skillet or grill pan over medium-high heat and brush lightly with oil. Cook the patties for about 5–6 minutes on the first side without moving them, then flip and cook for another 5–6 minutes on the other side, or until the internal temperature reaches 165°F.
Prepare the Sauce: (optional) While the patties cook, whisk together the mayonnaise, chopped chipotle peppers, and lime juice in a small bowl.
Serve: Melt a slice of pepper jack or cheddar cheese on the patties during the last minute of cooking, if desired. Serve warm on your favorite toasted buns topped with the chipotle mayo.