Source: Epicurious - recipe by Molly Stevens, Bon Appetit 2007
adapted by http://theresalwaysthyme.blogspot.com/
4 tablespoons unseasoned rice vinegar
2 tablespoons finely grated peeled fresh ginger, more or less, to taste
3 tablespoons peanut oil
4 tablespoons Asian sesame oil
3 tablespoons soy sauce
3 tablespoons honey
tablespoon chopped fresh cilantro, more or less to taste
1 jalapeno or serrano chile, seeded, minced
salt and freshly ground pepper
4 1 1/4 -inch-thick tuna steaks
1 large red bell pepper, cut into thick slices, length-wise
1 poblano pepper, cut in slices, length-wise
1 large sweet onion (such as Maui or Vidalia), cut into thick slices
Put the vinegar, oils, ginger, soy sauce, chile, and cilantro in a jar, close the lid, and shake vigorously to combine; season to taste with salt and pepper. Add tuna to a ziploc bag and pour some of the marinade from the jar, reserving some of the marinade to serve. Zip the bag closed and shake to cover tuna with marinade. Refrigerate at least 30 minutes and up to 45 minutes.
Spray grill rack with nonstick spray. Prepare barbecue (medium-high heat). Grill tuna, peppers, onions to desired doneness, turning frequently, about 4 minutes total for medium-rare. Transfer to platter. Drizzle reserved marinade over; sprinkle with chopped cilantro.