Melt the butter in a large pan over medium heat.  Add the garlic to the melted butter.  Add the flour and whisk until smooth, about 1-2 minutes.

Gradually pour the chicken broth into the pot while whisking constantly.  Allow the broth to cook for about 2 minutes, until thickened.

Add the tortellini to the pan and bring to a boil.  Cook for 4 minutes, stirring occasionally. 

Add the shredded chicken, Cajun Blue Cheese Sauce, and 1 cup of the cheese to the pot and stir well.  Top the tortellini mixture with the remaining cup of cheese, cover the pot with a lid for 2-3 minutes, until cheese is melted.