Whip the cream and sugar in a chilled bowl until the cream begins to thicken. Gradually whip in the white wine, lemon juice, and lemon zest. Continue to whip until light and fluffy, but not grainy. Cover and chill until serving time. Serve in chilled parfait glasses, garnished with a dash of nutmeg, a sprig of mint, and a slice of lemon. Syllabub should be eaten with a small spoon, and savored!