To make a thicker, creamier sauce, I increased the amount of walnuts in the recipe from 2 tablespoons to 1 cup. I also made a few modifications to the cooking technique. The original recipe adds the ground walnuts at the end of the cooking process. I chose to follow the traditional method of cooking the ground walnuts with the onions until browned (deepening the flavor of the walnuts), and letting the nuts braise with the chicken from start to finish. I also took the extra step of reducing the walnut sauce at the very end for a thicker sauce - it's really a matter of preference, depending on whether you like a thick or thin sauce. I ended up with a creamy, thick sauce with no little walnut pieces floating around.