Grilled Tuna Steaks With Vinaigrette

1A. FOR A CHARCOAL GRILL: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour evenly over half of grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.
1B. FOR A GAS GRILL: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. (Adjust burners as needed to maintain hot fire.)
2. Clean cooking grate, then repeatedly brush grate with well-oiled paper towels until grate is black and glossy, 5 to 10 times.
3. Meanwhile, whisk vinegar, thyme, mustard, honey, 1⁄2 teaspoon salt, and pinch pepper together in large bowl. Whisking constantly, slowly drizzle oil into vinegar mixture until lightly thickened and emulsified. Measure out 3⁄4 cup vinaigrette and set aside for cooking fish. Reserve remaining vinaigrette for serving.
4. Pat fish dry with paper towels. Generously brush both sides of fish with vinaigrette and season with salt and pepper. Place fish on grill (hot side if using charcoal) and cook (covered if using gas) until grill marks form and bottom surface is opaque, 1 to 3 minutes.
5. Flip fish and cook until opaque at perimeter and translucent red at center when checked with tip of paring knife and registers 110 degrees (rare), about 1-1⁄2 minutes, or until opaque at perimeter and reddish pink at center when checked with tip of paring knife and registers 125 degrees (medium-rare), about 3 minutes. Serve, passing reserved vinaigrette.

GRILLED TUNA STEAKS WITH PROVENÇAL VINAIGRETTE
Substitute 1 tablespoon minced fresh oregano for thyme and add 1⁄4 cup chopped pitted oil-cured black olives, 2 tablespoons minced fresh parsley, 2 minced anchovies, and 1 minced garlic clove to vinaigrette.

GRILLED TUNA STEAKS WITH CHARMOULA VINAIGRETTE
Substitute 2 tablespoons minced fresh parsley for thyme and add 1⁄4 cup minced fresh cilantro, 4 minced garlic cloves, 1 teaspoon paprika, 1 teaspoon ground cumin, and 1⁄2 teaspoon ground coriander to vinaigrette.

GRILLED TUNA STEAKS WITH SOY-GINGER VINAIGRETTE
Substitute rice vinegar for red wine vinegar and 2 thinly sliced scallions for thyme. Omit salt and add 3 tablespoons soy sauce, 1 tablespoon toasted sesame oil, 2 teaspoons grated fresh ginger, and 1⁄2 teaspoon red pepper flakes to vinaigrette.