- 6 tablespoons (3/4 stick) butter
- 1 cup chopped shallots (about 4 large)
- 1 cup chopped celery (about 3 stalks)
- 2 cups wild rice (about 12 ounces)
- 4 1/2 cups (or more) low-salt chicken broth
- 1 tablespoon dried thyme
- 1/2 teaspoon coarse kosher salt
- 1 cup long-grain brown rice
- 1 1/2 cups red seedless grapes (about 8 ounces)
- 1 1/2 cups green seedless grapes (about 8 ounces)
- 2 tablespoons olive oil
- 1 1/2 teaspoons balsamic vinegar
- 1 1/2 cups walnuts, toasted, chopped
- 1 tablespoon finely grated orange peel
- Melt butter in heavy large saucepan over medium heat. Add shallots and celery. Cook until soft, stirring frequently, about 8 minutes. Add wild rice, 4 1/2 cups broth, thyme, and 1/2 teaspoon coarse salt; bring to simmer. Cover, reduce heat to medium-low, and simmer 30 minutes. Add brown rice, cover, and simmer until rice is tender but firm, adding more broth by 1/4 cupfuls if dry, about 40 minutes longer. DO AHEAD: Can be made 1 day ahead. Cool slightly; cover and chill. Rewarm over medium-low heat before using, adding more broth by 1/4 cupfuls if dry.
- Meanwhile, preheat oven to 350°F. Place grapes on rimmed baking sheet. Drizzle with oil; toss. Roast grapes until beginning to wrinkle, about 15 minutes. Transfer to bowl; toss with vinegar. DO AHEAD: Can be made 4 hours ahead. Let stand at room temperature.
- Add grapes and any juices, walnuts, and orange peel to hot rice; toss well. Season to taste with salt and pepper.