Other than perhaps Thanksgiving, the Passover seder is maybe the largest and most tradition-dictated meal many American Jews will prepare each year. The eight-day holiday that begins this week on April 1 often is marked with a seder on the first and second nights and may include such staples as brisket, matzoh ball soup, haroset and kugel. (Also parsley, lots of parsley.) If you need ideas for the festive spread, we have them in spades. But what about the rest of the week?