On December 21st, usher in the winter solstice with a luxurious four-course truffle-infused dinner at Equinox, where chef/owner Todd Gray’s inventive use of the prized tubers will culminate with a black-truffle ice cream adorned by Moscato pears, almond brittle and caramel. Book now while there's still space (7 PM; $250 per person; 202-331-8118).