Cover a 10"round metal rack with foil and poke holes in several places with a fork.In a 12" heavy skillet(at least 3"deep) spread 2 rounded tbsps. untreated hickory chips and top with rack.

Arrange mushroom caps, stemmed side up, in one layer on rack and cook over moderate heat until chips begin to smoke. Cover skillet immediately with a tight fitting lid or foil and smoke 10 minutes. Remove skillet from heat and let stand,covered, until mushrooms are firm-tender,about 5 minutes. Cool hickory chips completely and discard. Smoked mushrooms may be made 1 day ahead and kept chilled, covered.