For curd: Whip eggs and sugar until very light and fluffy with a whip attachment. Gradually mix in lemon juice and rind. Place over boiling water and cook, whisking until extremely thick, about 5 10 minutes. Remove from heat and whisk in butter. Pour into a container, cover with plastic wrap and chill overnight to stiffen.
For tart dough: Lay one sheet of phyllo on work surface. Brush with clarified butter and sprinkle with sugar. Repeat the process with the second and third sheets. Cut into 3-inch squares.
Lay 18 tartlet molds upside down on a sheet pan. Lay 1 square of phyllo over each pan, then place a second one on top of phyllo to help form tartlet shells. The square corners will spread out flat on the sheet pan. Bake in this upside down position weighted down with another sheet pan at 375 degrees Fahrenheit until golden brown. Let phyllo cool slightly, but while still warm remove from molds. Cool completely then fill with lemon curd by piping with a plain tip.
For meringue: Whip egg whites until stiff but not dry then add the brown sugar gradually and continue whipping until stiff. Pipe onto lemon curd with a star tip and brown with a blow torch or under the broiler.