When Kramer spills the kreplach, three small pieces land near the edge of the counter. In the next shot, there are four pieces, which are noticeably larger and further from the edge.
When at the singles function, Jerry (Jerry Seinfeld) asks Elaine (Julia Louis-Dreyfus), "Have you tried the Hamantashen?" Elaine replies, "I can't get off the kishkas." Although 'Hamantashen' are indeed a Jewish food, they are small pastries that wouldn't be eaten with a knife and fork. Additionally, the name of the dish Elaine likes is called 'kishka' (without the 's').
When Frank (Jerry Stiller) decides he's had enough of Estelle's (Estelle Harris) cooking, he yells, "Give me that spatula", but grabs an egg, not a spatula.
In this episode it's revealed that Frank (Jerry Stiller) hasn't cooked since he was in Korea, yet back in The Doorman (1995), George (Jason Alexander) has a complaint about his father making kishka.
Kramer (Michael Richards) has a lot of trouble making Jewish delicacies, but in The Truth (1991), he had no problems when making African delicacies.