CUT THE TURKEY BREAST AGAINST THE GRAIN INTO 6 PIECES OF ABOUT THE SAME SIZE.
LINE A SMOOTH WORKING SURFACE WITH PLASTIC WRAP AND ARRANGE THE CUTLETS OVER THE PLASTIC. COVER WITH ANOTHER SHEET OF PLASTIC WRAP AND GENTLY POUND TURKEY UNTIL 1/4" THICK. SEASON LIGHTLY WITH SALT, SET ASIDE.
IN A MEDIUM BOWL, MIX THE CHEESE, BREADCRUMBS AND PARSLEY UNTIL WELL COMBINED. PLACE NEXT TO A BOWL FILLED WITH FLOUR. IN ANOTHER BOWL,ADD THE EGG/WATER MIXTURE AND THEN THE BREAD CRUMB MIXTURE IN ANOTHER BOWL.
BREAD CUTLETS BY DIPPING FIRST IN FLOUR, THEN IN EGG AND FINALLY IN BREAD CRUMB MIXTURE. SET THEM ON A CLEAN PLATTER OR BAKING SHEET IN ONE LAYER.
HEAT 1/2 CUP OF OLIVE OIL IN A LARGE SKILLET UNTIL VERY HOT. FRY CUTLETS WITHOUT OVERLAPPING UNTIL CRISPY AND GOLDEN BROWN. AS SOON AS THE CUTLETS TURN GOLDEN BROWN, TRANSFER TO A PLATE WITH PAPER TOWELS TO DRAIN OFF ANY EXCESS GREASE. KEEP WARM IN A PREHEATED 200° OVEN.
DRAIN THE TUNA OF ANY EXCESS OIL AND TRANSFER TO A FOOD PROCESSOR OR BLENDER. PULSE SEVERAL TIMES TO BREAK DOWN THE TUNA. ADD THE LEMON JUICE AND CAPERS AND PROCESS FOR 20 SECONDS. ADD THE MAYONNAISE AND WITH THE MACHINE RUNNING, DRIZZLE IN THE REMAINING 1/2 CUP OLIVE OIL. TASTE AND SEASON WITH ADDITIONAL SALT AND LEMON JUICE IF NEEDED.