Make the basil aioli: Combine the mayo, wasabi, garlic, olive oil, basil, and spinach in a small blender or food processor and blend until smooth.
Generously season both sides of the tuna with pinches of salt and pepper and rub with the 7 spice blend, if using. Heat a drizzle of olive oil in a pan and sear the tuna for 1 minute on each side. Remove from the pan, let cool, and slice into thin strips.
Prepare the rolls: Place a small bowl of water and a kitchen towel near your work area as your hands will get sticky. Place one nori sheet, glossy side down, onto a bamboo mat and press a handful of rice onto the lower two-thirds of the sheet. At the bottom of the rice place your toppings. Don’t overfill or it will be more difficult to roll. Use the bamboo mat to tuck and roll the nori. Once rolled, use the bamboo mat to gently press and shape the roll. Place the roll to the side, cut side down. Repeat with remaining rolls.
Use a sharp chef’s knife to cut the sushi. Wipe the knife clean with a damp towel between cuts.
Serve sushi alongside the basil aioli.
The Basil Aioli recipe comes courtesy of Timothy Thomas, via the Central Market Cooking School.
Recipe by Love and Lemons at https://www.loveandlemons.com/seared-tuna-roll/