PUT TUNA STEAKS (STILL WRAPPED) IN THE FREEZER FOR 30 MINUTES BEFORE COOKING.
PEEL THE POTATOES. CUT INTO 1-INCH DICE. PLACE IN A STEAMER AND STEAM FOR ABOUT 15 MINUTES OR UNTIL DONE.
WASH THE ARUGULA, SPIN DRY AND WRAP IN TEA TOWEL.
CORE THE PEPPER. REMOVE ALL SEEDS. SLICE INTO 1/2-INCH STRIPS. COOK IN A FRYING PAN IN ABOUT 1/2 CUP OF OLIVE OIL ON A LOW FLAME, TURNING FREQUENTLY. IT'S OKAY IF THEY CHAR A BIT.
HEAT A CAST IRON PAN OVER A HIGH FLAME FOR ABOUT 3 MINUTES.
TAKE THE TUNA STEAKS FROM THE FREEZER. DRY WITH PAPER TOWELS. SALT AND PEPPER.
WHEN THE PAN IS VERY HOT, PLACE THE TUNA STEAKS DIRECTLY IN THE PAN. (YOU DON'T NEED OIL. THE TUNA HAS PLENTY.) COOK FOR ABOUT 3 MINUTES ON ONE SIDE. FLIP AND COOK ON THE OTHER SIDE. TUNA SHOULD BE CHARRED ON THE OUTSIDE BUT RARE IN THE CENTER.
DIVIDE ARUGULA ON TWO PLATES. HEAT UP THE PEPPERS AND ADD A SPLASH OF VINEGAR. ARRANGE THE PEPPERS ON TOP OF THE ARUGULA AND DRIZZLE WITH OIL FROM THE PAN.
PLACE THE TUNA STEAKS ON TOP OF THE ARUGULA SALAD. TOP WITH A HEALTHY DOLLOP OF LEMON AIOLI.
TOSS STEAMED POTATOES WITH A LITTLE OLIVE OIL AND SPOON ONTO EACH PLATE.
MOST IMMERSION BLENDERS COME WITH A TALL BEAKER. IF YOURS DOESN'T, USE A WIDE-MOUTHED JAR SUCH AS A MASON JAR.
PUT A HEALTHY PINCH OF SALT, FRESH-GROUND PEPPER, 1 TSP OF DRIED MUSTARD, THE JUICE OF ONE LEMON, ONE EGG, 1/2 CUP OF VEGETABLE OIL, AND 1/2 CUP OF OLIVE OIL IN THE CONTAINER.
POSITION THE BLENDER SO IT TOUCHES THE BOTTOM OF THE CONTAINER WITH ALL THE INGREDIENTS. TURN IT ON AND SLOWLY RAISE IT TOWARDS THE SURFACE. BY THE TIME YOU GET THERE YOU SHOULD HAVE AIOLI, BUT YOU MIGHT WANT TO BLEND IT A BIT MORE BY RAISING AND LOWERING THE BLENDER. IT SHOULD BE THICK, VISCOUS AND A BIT FLUFFY.
