In a large skillet over medium heat, add olive oil. Once hot, toss in the diced onion, garlic, and bell pepper. Sauté until the veggies are soft, about 3-4 minutes.

Add the ground chicken to the skillet. Stir well to combine with the veggies, cooking until the chicken is browned and fully cooked, approximately 5-7 minutes.

Sprinkle in the Cajun seasoning, mixing thoroughly. Let the spices cook for a minute or two to develop their flavors.

Pour in the diced tomatoes (with their juice), chicken broth, and Worcestershire sauce. Stir everything together, bringing the mixture to a simmer. Reduce heat and let it cook for about 10 minutes, stirring occasionally.

While the chicken is simmering, slice your hamburger buns in half and lightly toast them if desired.

Spoon generous portions of the Cajun chicken mixture onto the toasted buns, topped with shredded lettuce and slices of tomato. Serve immediately and enjoy!