Last night I enjoyed a classic bistro meal at Mimosa cafe: cheese and onion tart; endive salad with cheese, nuts and dried fruits; filet of sole cooked perfectly on mashed potatoes, sauced with red peppers; and pear financier; the whole washed down with bitter Alsatian beer. Now to the point: the place was all but deserted, four tables occupied when we arrived at around 7, no more, in fact maybe only two or three, when we departed at 8:30. Another bad sign: they didn't have their usual cassoulet, said it wasn't ready. Is this place on the way out? How could that be? They have always served reasonably priced well-cooked food in a warm, charming atmosphere. Was this, Jan. 2, just an off-night for restaurants everywhere?