In a large skillet, heat a tablespoon of olive oil over medium-high heat. Add the ground chicken, breaking it apart with a spatula, and sauté for 5-7 minutes, or until browned and cooked through.

Stir in the finely chopped onion and cook for 3-4 minutes, until it becomes translucent. Add the minced garlic and sprinkle in the Cajun seasoning, cooking for another minute until fragrant.

Mix in a couple of tablespoons of tomato paste, stirring until it glistens. Pour in the low-sodium chicken broth, tomato sauce, and Worcestershire sauce, stirring well to combine. Simmer uncovered on low heat for 8-10 minutes.

In a separate saucepan over medium heat, melt 2 tablespoons of unsalted butter. Whisk in an equal amount of all-purpose flour to form a roux, cooking for about 1-2 minutes until golden.

Gradually add 1 cup of whole milk, stirring until the mixture thickens and coats the back of a spoon, which should take about 4-5 minutes.

Reduce the heat to low, then slowly mix in 1.5 cups of freshly shredded sharp cheddar cheese and a pinch of paprika. Continue stirring until the cheese is completely melted and the sauce is smooth.

Butter the cut sides of brioche buns. Heat a skillet or broiler to medium and toast the buns until they are golden brown, about 2-3 minutes.

To assemble, spoon a generous portion of the chicken mixture onto the bottom half of each toasted bun. Ladle the warm cheese sauce over the top, and finish with the top bun.