From Cooking Light Magazine a few years ago but doesn't seem to be on their web site any more.
1/4 Cup Yellow Miso (soybean paste) Or brown
1/4 Cup Mirin (sweet rice wine)
1/4 Cup Dry White Wine
1 Tablespoon Wasabi Powder
(I never use this much. More like a teaspoon)1 Tablespoon Rice Vinegar
1 1-Pound Flank Steak, trimmed
Cooking spray
Combine first five ingredients (Miso, Mirin, Wine, Wasabi and Vinegar) in a small bowl. Stir well with a whisk. Combine miso mixture and steak in a large zip top or vacuum bag. Seal and marinate in refrigerator 2 hours or longer.
Prepare grill or broiler.
Remove steak from bag, reserving marinade. Place steak on grill rack or broiler pan coasted with cooking spray. Grill or broil 6 minutes each side or until desired degree of doneness, basting occasionally with reserved marinade.
Then reduce what marinade you don't use for basting and serve as sauce.
Yield: 4 servings (serving size 3 oz.)
NOTE: If using larger steak--ours seem to come in at 1.75 pounds, I double the marinade. )