Pico Blvd. is lined with Jewish delis, but stray from the pack and head to MacArthur Park and Langer’s, which has been ladling matzoh ball soup since 1947. And while it began life as a 12-seat counter, it has transformed to a massive space—decked out with booths and that classic counter.Equally ample is the menu, with all of the requisite standards, such as latkes, blintzes and chopped liver. Breakfast is served all day, but if you’re here for the first time, opt for the hot pastrami (provided by RC Provisions in Burbank) sandwich. Sugar-cured, seasoned and smoked; then piled with cheese, sauerkraut and grilled between two slices of rye—it’s the king of the castle. The only way to make this meal better is to end with a slice of sinfully rich cheesecake.