Teriyaki-Grilled Tuna with Water Chestnuts
| 1/4 | cup reduced sodium soy sauce |
| 2 | tablespoons rice-wine vinegar |
| 2 | tablespoons dry sherry |
| 6 | garlic cloves, minced |
| 1 | tablespoon minced peeled fresh ginger |
| 2 | teaspoons honey |
| 1/4 | teaspoon freshly ground pepper |
| 1 | (8 ounce) can whole water chestnuts, drained |
| 1¼ | pounds tuna steaks, cut into 4 pieces |