In a large skillet, heat 1 tablespoon of oil over medium heat. Add 1 diced onion and 1 diced green bell pepper, sautéing for 7–8 minutes until soft and fragrant. Stir in 2 minced garlic cloves for the last minute.

Increase the heat slightly and add 1 pound of crumbled ground chicken to the skillet. Cook for about 5–7 minutes, breaking apart with a spatula, until browned and cooked through. Season with 2 tablespoons of Cajun spice blend.

Lower heat to medium-low and stir in 1 cup of tomato sauce, 1/4 cup of ketchup, 1 tablespoon of Worcestershire sauce, and 2 teaspoons of brown sugar. Bring to a gentle simmer and cook for 10–15 minutes until thickened.

Preheat the oven to 400°F (200°C). Slice burger buns in half and place them cut-side up on a baking sheet. Toast for 4–5 minutes until golden.

Remove the sauce from the heat and top with mozzarella and cheddar cheese. Cover and let sit for a few minutes to melt the cheese.

Using a spoon, heap the Cajun chicken mixture onto the toasted buns. Serve immediately.