In a large skillet, heat a drizzle of olive oil over medium heat. Add diced onions, green bell peppers, and minced garlic. Sauté for about 7-8 minutes until softened and fragrant.

Add 1 pound of lean ground chicken to the skillet. Break it apart and mix with the veggies. Sprinkle Cajun spice blend and cook for approximately 8-10 minutes until browned.

In a separate bowl, combine tomato sauce, ketchup, Worcestershire sauce, and brown sugar. Once the chicken is cooked, pour this sauce over the mixture and simmer for 10-15 minutes.

Preheat your oven to 400°F (200°C). Slice the hamburger buns in half and toast them on a baking sheet for 4-5 minutes.

Remove the toasted buns and spoon a generous amount of the Cajun chicken mixture onto each bottom half. Top with shredded cheese and place the bun tops on each sandwich.