Begin bowling a pot of water to cook the noodles, and cook according to package instructions.
Make the rub: combine the garlic powder, coriander, dried ginger and turmeric in a small bowl.
Sprinkle about half the rub over one side of the tuna steak, then gently rub it into the fish. Turn the tuna over and repeat the process of applying the rub.
Make the sauce for the noodles: combine the soy sauce, canola oil, honey and rice wine vinegar in a small bowl.
When the noodles are cooked, drain the noodles. Toss the drained noodles immediately with the sauce. Set aside while you cook the tuna.
Coat a nonstick skillet with oil spray. Heat on medium high. Add the tuna steak when the skillet is hot, and sear for 90 seconds. Turn the tuna over, and sear for another 90 seconds. Remove the tuna to a platter. Cut the tuna into slices about 1/2 inch thick.
Place a serving of the noodles in a bowl. Arrange 4 slices around the top of the noodles. Sprinkle a bit of scallion and bell pepper over the tuna and noodles. Repeat the process for the other bowls you are preparing. Enjoy!