By definition, since it's made with cooked chicken pieces and no tomatoes, it's going to be thinner than traditional chili (such as no-bean chili, pumpkin chili, or turkey chili). The best way to make it thicker is to add just enough broth to get it to a stew consistency. Don't add too much liquid and then try to reduce it. Especially in this recipe, where the chicken is already cooked. This will just dry the chicken out. My recipe calls for 4 cups of chicken broth. If you find that it's not thick enough to your liking, try using just 3 cups next time. If you don't mind a little cornstarch, another trick is to whisk 1 tablespoon of cornstarch into the cold heavy cream before you add it to the chili. Make sure to whisk it well.