Luis Ruiz is one of my longtime line cooks; he is a master at producing ragù. I often think he instinctively knows how, because he has a great palate and perhaps his family taught everyone the basics of good Puebla, Mexico, cookery. We have evolved this recipe, and it keeps evolving. I am not the biggest fan of tomato concentrate (nor ketchup, for the same reason). It may have been invented by Escoffier, but I find it over-cooked, over-reduced, and it doesn