1. Combine wine, vinegar, sugar, and 1/4 teaspoon pepper in a small saucepan over medium-high heat. Simmer until slightly thickened and syrupy, 25 to 30 minutes. Remove from heat, and set aside.
2. Combine tomatoes, 1 teaspoon olive oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a medium bowl. Toss, and set aside
3. Heat grill to medium hot. Combine haricots verts, lemon juice, remaining teaspoon olive oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a bowl; toss well. Arrange beans on the grill and cook, turning, until just limp and lightly charred, 2 to 4 minutes. Transfer to a serving platter.
4. Sprinkle remaining teaspoon salt and 1/4 teaspoon pepper on all sides of tuna steaks. Brush wine-and-vinegar mixture on tops and sides of steaks and place, glazed side down, on grill. Grill, brushing with more glaze, until lightly charred, about 3 minutes per side for rare, 6 to 7 for well done. Transfer to serving platter with beans. Add basil to tomatoes, toss, and spoon over tuna. Serve immediately.

Yield: 6 servings