PEEL THE POTATOES AND SLICE IN 1/4-INCH ROUNDS. PLACE IN A STEAMER AND STEAM UNTIL DONE. DRAIN IMMEDIATELY AND PLACE IN A BOWL. TOSS WITH THE COLD WHITE WINE AND ALLOW TO SIT UNTIL THEY COOL.
MEANWHILE, PEEL THE ONION, SLICE LENGTHWISE IN HALF, THEN INTO 1/4-INCH HALF MOONS.
PUT A GENEROUS PINCH OF SEA SALT AND SEVERAL GRINDINGS OF FRESH PEPPER IN THE BOTTOM OF A SERVING BOWL. ADD 3 TBSPS OF VINEGAR. WHISK IN 2 TBSPS OF MUSTARD. TOSS WITH THE ONIONS AND ALLOW TO SIT FOR 5 MINUTES.
WHISK IN 3 TBSPS OF NUT OIL AND ABOUT 1/3 CUP OF OLIVE OIL. THE MIXTURE SHOULD BE VISCOUS.
DRAIN THE POTATOES AND TOSS GENTLY WITH THE DRESSING.
DRY THE SHRIMP BETWEEN SEVERAL LAYERS OF PAPER TOWELS.
TRIM AND PEEL GARLIC CLOVES. SLICE THINLY.
HEAT A GENEROUS SPLASH OF OLIVE OIL IN A FRYING PAN. WHEN THE OIL SMOKES, ADD ALL THE SHRIMP. SALT AND PEPPER. SAUTÉ ABOUT A MINUTE, THEN TURN OVER AND COOK ANOTHER MINUTE UNTIL THEY'RE PINK AND BARELY COOKED.
REDUCE HEAT TO LOW, TOSS IN THE GARLIC AND STIR UNTIL YOU JUST SMELL THE GARLIC.
SPOON THE SHRIMP OVER THE POTATO SALAD. TOSS WITH CHOPPED HERBS.
SERVES 4