1Season fish with salt and pepper. Rub 1 tablespoon of the olive oil and all of the thyme and tarragon on each tuna fillet. Press chopped macadamias on each side of the fillets.
2Put garlic, shallots, and remaining 1 tablespoon olive oil in sauté pan and heat on high until oil bubbles. Carefully place fish in the pan and sear about 15 seconds on each side for rare; 30 seconds on each side for medium rare. If you prefer well done fish, start at a low heat and sauté until done.
3Serve immediately, each serving garnish with a fresh lemon wedge.