1 1/2 pounds small new potatoes, scrubbed
1/4 teaspoon coarse salt, plus a pinch
2 tablespoons Dijon mustard
2 tablespoons soy sauce
2 tablespoons olive oil
1/4 teaspoon freshly ground pepper
Vegetable oil, for grate
Place potatoes in a medium pot; add enough water to cover by 1 inch. bring to a boil; add a pinch of salt. cook until potatoes are barely tender when pierced with a knife, 10 to 20 minutes, depending on their size. Drain; rinse under cold running water. Cut potatoes in half.
In a medium bowl, whisk together the mustard, soy sauce, oil, 1/4 teaspoon salt, and pepper. Add the potatoes and toss to coat. cover with plastic wrap and let stand at room temperature 1 hour.
Build a charcoal fire in an outdoor grill and let burn until covered with white ash. If you are using a gas grill, preheat it on high. Lightly oil the cooking grate. Place the potatoes on prepared grate and cover grill. Cook, turning occasionally and basting with the marinade, until brown and tender, about 10 minutes. Serve immediately. Serves 4 to 6.
