Marinate the tuna. Mix all of the marinade ingredients together in a glass measuring up and set aside. Rinse the tuna steaks and pat them dry with paper towels. Pour a little of the marinade into a medium-sized baking dish, then lay the fish in and pour the rest of the marinade over the fish. Cover with plastic and refrigerate until ready to cook.
Make the dressing. Whisk all the ingredients together in a small bowl. If you are heat-averse, use only 1 t of the sriracha. Taste and adjust heat (sriracha), acid (lime juice), and salt (soy sauce). Add enough water to get it to the desired consistency.
Cook the rice. Measure the rice into a medium-sized sauce pan, then rinse it. Pour off as much water as you can, then add 2 ¼ cups of water. Bring to a hard boil, then turn the heat to low, cover, and set a timer for 25 minutes. Don’t lift the lid. When the timer goes off, turn off the heat and allow the rice to rest for 10 more minutes. Then check it. There should be no water at the bottom when you tip the pot. Pop the top back on and set aside until ready to plate.
While the rice cooks, mis en place the toppings. Mix the lime juice and vinegar in a medium-sized bowl. Then chop the bok choy, toss it in the lime and vinegar and lift it out with your hands. Set it aside in a bowl. Repeat this with thinly sliced radishes and grated carrots. Discard any remaining vinegar and lime juice.
Get a steamer ready for the broccoli, but don’t steam it just yet. This is the last step before plating. So you want it to be ready to go.
Sear the tuna. Remove the tuna from the fridge and set a cast iron skillet over high heat. The skillet is ready when a few drops of water dance and pop on the surface. Add a small amount of high-smoke-point oil to coat the surface of the pan, then immediately place the steaks in the pan and set the marinade aside. Use a meat fork to place the steaks where you want them, because when they hit the pan, they will stick. But they will release once the bottom is seared. The point is, don’t try to move them. Cover with your screen and set a timer for 1 ½ minutes for medium rare, 2 ½ minutes for medium, or 3 minutes for medium-well. When the timer goes off, flip them and cover them again with the screen. Set your timer again. Remove them from the heat to a platter, cover with foil and set aside.
Pour the marinade into the skillet and stir. It will foam and bubble and look pretty gnarly. Turn the heat down enough so it doesn’t boil over and continue to stir until the mixture thickens. Then turn off the heat and remove the marinade to a glass measuring cup or pour bowl. Pour a little water into the skillet while it is still hot and mix it around to loosen all the stuck bits and make it easier to clean later.
Steam the broccoli while you assemble the bowls. Steam until it is bright green and still a bit al dentè.
Assemble the Poke bowls. Put a scoop of rice at the bottom of each bowl, then place all the vegetables in nice little piles, leaving space for the tuna and the broccoli.
Pour the sesame seeds onto a small plate and pour some of the marinade onto another small plate. Take out each tuna steak and coat with the marinade, then the sesame seeds, then add to each bowl. Add the steamed broccoli and drizzle with the dressing.
Involved? Yes. Worth it? Totally!