In a large skillet, heat a drizzle of olive oil over medium heat. Add diced onion, green bell pepper, and minced garlic, and sauté for about 7-8 minutes until soft.

Add 1 lb of lean ground chicken to the skillet with the sautéed vegetables. Cook for 5-6 minutes until browned.

In a separate bowl, combine tomato sauce, ketchup, Worcestershire sauce, and brown sugar. Pour into the skillet, stirring to blend.

Reduce heat to low and simmer the filling for 10-15 minutes, stirring occasionally. Adjust consistency with water if needed.

Preheat oven to 400°F (200°C). Place hamburger buns on a baking sheet and toast for 4-5 minutes.

Spoon the Cajun Chicken filling onto the bottom half of each toasted bun. Add cheese if desired before topping with bun lids.

Serve immediately with sides like Cajun fries or coleslaw.