There are certain rules that determine what food and combinations of food are kosher and what is not. While less than 1 percent of the US lives by all the rules, much of what is referred to as "Jewish food" has entered the mainstream of dining. Can anyone resist a matzo ball soup or a tasty brisket? These recipes here in "Classic Jewish Comfort Food Cookbook" have been kept kosher, but they can be adjusted to individual tastes and circumstances.