Elizabeth Yastrzemski, a baker and floral and garden designer, will lead a workshop on the making of beach plum jelly next Thursday night at 6 at the Rogers Mansion in Southampton. Those interested can register by calling the museum. The cost is $35, or $25 for museum members. Rowdy Hall in East Hampton has reintroduced its dinner-and-a-movie special. Sunday through Wednesday, a beef or turkey burger can be ordered along with a voucher for the East Hampton Cinema, for $22.