1. Prepare the noodles. In a large pot, bring 1 gallon water to a boil over high heat. Add 4 tsp. salt, then add spaghetti. Cook 8 minutes, just until al dente. Drain.
2. While water comes to a boil, combine sesame oil, garlic, ginger, soy sauce, tahini, vinegar, and chili sauce in a large serving bowl. Mix well.
3. Add drained noodles, carrot, scallion, and bean sprouts to the sesame mixture and toss well to combine. Set aside.
4. Prepare tuna. Rinse steaks and pat dry. Place sesame seeds in a shallow dish. Rub outside of each steak with olive oil. Sprinkle with salt and pepper. Lay each steak flat in the sesame seeds, and press gently until seeds adhere. Flip steak and press seeds into other side. Repeat until all steaks are coated with seeds.
5. Spray an extra-large nonstick skillet with olive oil cooking spray and heat over medium-high heat. Add tuna steaks. Sear 3 minutes, then flip and sear 3 minutes on the other side, or until sesame seeds are toasted and outside of steak is cooked; inside should be pink but not raw. Serve immediately with sesame noodles on the side.
Source: Hannaford fresh Magazine, July - August 2009