- 1 1/2 pounds small new potatoes, scrubbed (if using larger potatoes, cut into 1-inch chunks)
- 1/4 tablespoon coarse salt, plus more for cooking water
- 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 stockpot, and add enough water to cover by 1 inch. Bring to a boil. Add a large pinch of salt. Cook until potatoes are barely tender when pierced with the tip of a knife, 10 to 20 minutes, depending on their size. Drain, and rinse under cold running water until cool enough to handle. Cut potatoes in half.
- In a medium bowl, whisk together mustard, soy sauce, olive oil, 1/4 teaspoon salt, and pepper. Add the potatoes, and toss to coat. Cover with plastic wrap and let stand at room temperature for 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 on high.
- Lightly oil the cooking grate with vegetable oil. Place potatoes on the cooking grate, and cover grill. Cook, turning occasionally and basting with the marinade, until brown and tender, about 10 minutes. Serve immediately.