I was thrilled when I saw a video of Mark making this curry, so I decided to give it a try. For the first time I conjured up the most delicious homemade Japanese curry. I used beef shanks for this recipe, but like what he said, you can use any type of meat, poultry, or you can even turn this curry into a completely vegetarian meal. I also cooked the roux a little longer, resulting a much darker curry. One little obstacle was that I had trouble of finding tonkatsu sauce, I did find a bottle of katsu sauce, which I am not entirely sure what the different between tonkatsu and katsu. The recipe only need 1 tablespoon of this sauce, that leave me with a whole bottle of katsu sauce, I don't even know what I am going to use it for. I better e-mail him and ask for advice what to cook next with this sauce. Thank you to Mark for sharing the recipe, and show us how to make the authentic Japanese curry.