While I'm not familiar with Tom Ka, we do eat hot and sour soup like it's going out of style and we all love Tom Yum, so this soup seemed like a safe bet. As the 5 stars would indicate, we were spot on. The whole family thought the recipe was awesome. We didn't have any fresh shiitakes, but reconstituted dried ones worked just fine. Our only other deviation was to increase the vinegar a bit since we love the "sour" but other than that we stuck to the recipe. Thanks for a great soup, Chef#519123!