Preparing the Vegetables
Spray a skillet with cooking spray and heat over medium heat.
Add the onion and cook until translucent, then add garlic to release a fragrant aroma.
Add the carrots, bell pepper, tomato, and mushrooms, and cook until tender, about 5 to 7 minutes.
Remove from heat and let cool for about 20 minutes.
Preheat your outdoor grill and lightly grease the grates with oil.
Preparing the Patties
Mix ground chicken, bread crumbs, egg, seafood seasoning, salt, and pepper in a large bowl.
Form the mixture into patties and set them aside.
Grill the patties for 5 to 6 minutes per side until the meat is no longer pink and the juices clear. Use an instant-read thermometer to check that the internal temperature reaches 165°F (74°C).
Preparing the Chicken
Coat chicken breast halves with olive oil, paprika, garlic powder, onion powder, and salt.
Grill the chicken on medium-high heat for 3 to 5 minutes per side until it is cooked through and the cheese melts.
Final Steps and Assembly
Lightly toast your buns on the grill while the chicken is cooking.
Prepare toppings by caramelizing onions until soft and golden, and marinate the chicken if needed.
Place lettuce leaves and tomato slices on the bottom bun to assemble the burger, followed by the grilled chicken with melted cheese.
Top with caramelized onions and a dollop of mayonnaise, ketchup, or chili sauce.
Cover with the top bun and secure it with a sandwich skewer.