First make the marinade for the tuna by combining the olive oil, coconut aminos, rice vinegar, lime juice, fresh ginger, and garlic in a sealable plastic bag or nonreactive container.
Season the tuna steaks with salt and pepper on each side then place in the marinade. Turn to coat and place in the refrigerator for 30 minutes, turning half way through.
Meanwhile, whisk together the coconut aminos, lemon juice, rice vinegar, green onion, and fresh ginger in a small bowl to make the dressing for the salad. Set aside.
Using a vegetable peeler, shave the carrots, asparagus, and cucumber into long thin strips. For the carrot and cucumber rotate around the vegetables and stop when you reach the fibrous core/seeds. It may be easiest to do this with the vegetables flat on a cutting board.
Place the vegetable ribbons into a bowl and lightly coat with the dressing (about half), toss to mix well. Reserve the remaining dressing to use over the final dish and let the salad sit to allow the flavors to meld.
Heat the cooking fat in a skillet over a medium-high heat.
Sear each tuna steak for 1 1⁄2 – 2 minutes per side, depending on the desired doneness. Divide the shaved salad onto 4 plates, top each with a tuna steak and serve the reserved dressing to pour over the tuna as desired.