PREHEAT OVEN TO 350ºF (175ºC) GREASE CUPCAKE TINS WITH BUTTER. LINE EACH CUP WITH PUFF PASTRY DOUGH. SLICE LEEKS AND MUSHROOMS ABOUT 1/4 INCH THICK AND CHOP BACON INTO SMALL PIECES. SAUTÉE LEEKS AND MUSHROOMS UNTIL SOFTENED THEN ADD BACON AND COOK UNTIL BACON IS SLIGHTLY CRISPED. ALLOW TO COOL. IN THE MEANTIME, BEAT EGGS, ADD YOGURT, MOZZARELLA, AND A TABLESPOON OF WICKED WHITE TRUFFLE OIL. ADD SAUTÉED INGREDIENTS AND MIX WELL. POUR INTO PUFF PASTRY CUPS UNTIL FILLED AND BAKE FOR 20 MINUTES OR UNTIL EGG MIXTURE DOES NOT JIGGLE. SERVE WARM OR COLD TOPPED WITH CREME FRAICHE AND FRESH HERBS AND ENJOY!