Allow dressing to sit for awhile for flavors to blend
Aioli
In a small bowl, mix wasabi powder into mayonnaise until smooth using a spoon or small wisk
Add garlic powder and wisk until smooth
Add lime juice and wisk until smooth
Slowly stir in a bit of water to reach the desired texture
Salad
Prepare the salad just before searing the tuna
Add greens to a medium mixing bowl
Add a bit of dressing a spoonful at a time tossing with hand, tongs or spoons. Use only enough dressing to coat the leaves
Plate the greens
Sprinkle sliced red peppers and scallions over the greens
Tuna
Pat the tuna steak dry with paper towels
Spread sesame seeds onto a dinner plate or baking dish
Press the tuna onto sesame seeds coating all sides
Heat medium to large skillet to medium high heat
Melt the ghee and heat until it shimmers
Place tuna in skillet for 1-2 minutes until the cooked portion is about 1/8″ to 1/4″ thick, depending on your preferences. I like to rock the skillet a bit to get more ghee under and around the tuna
Turn the tuna over and continue to cook for 1-2 minutes.
Remove tuna from skillet to a cutting board
With a very sharp slicing knife, cut the tuna cross-grain into 3/16″ slices
Final Plating
Place tuna slices over salad showing off the beautiful interior