- 1 teaspoon coarse kosher salt
- 1 bay leaf
- 1 teaspoon fennel seeds
- 1 teaspoon dried lavender blossoms
- 3/4 teaspoon whole black peppercorns
- 1/2 teaspoon whole allspice
- 4 small or 2 large duck breast halves (about 1 3/4 pounds total)
- 2 tablespoons extra-virgin olive oil
- 2 garlic cloves, peeled, smashed
- 1 pound cavolo nero or other kale, thick center stems removed, leaves cut crosswise into 1-inch-thick slices (about 16 cups)
- 3/4 cup low-salt chicken broth
- 1 pound red seedless grapes, stemmed
- Grind first 6 ingredients in mortar with pestle or in spice mill until finely ground. DO AHEAD: Can be made 1 week ahead. Store airtight at room temperature.
- Score duck skin only (not flesh) in 1/2-inch diamond pattern. Sprinkle spice blend all over duck; gently massage into meat. Cover and chill overnight. Let stand at room temperature 1 hour before cooking. Position 1 rack in top third and 1 rack in bottom third of oven; preheat to 425°F. Heat oil in heavy large pot over medium heat. Add garlic and sauté until beginning to brown, about 3 minutes. Add kale; sprinkle with salt and pepper. Toss until kale wilts. Add broth and bring to boil. Reduce heat to low; cover and cook until kale is tender, 8 to 10 minutes. Uncover pot. Increase heat to high and cook kale until almost all liquid is absorbed, about 3 minutes. Set aside.
- Heat heavy large ovenproof skillet over high heat. Add duck breasts, skin side down, to skillet. Cook until skin is browned and fat is rendered, about 8 minutes. Transfer duck, skin side up, to rimmed baking sheet and place in oven. Roast until cooked to desired doneness, 3 to 5 minutes for small duck breasts and 8 to 10 minutes for large duck breasts for medium-rare. Tent with foil to keep warm. Let rest 10 minutes.
- Meanwhile, pour off all but 1 tablespoon fat from skillet. Add grapes to skillet and roast in oven until skins begin to split, about 15 minutes.
- Gently rewarm kale. Thinly slice duck breasts. Arrange sliced duck on plates, dividing equally. Spoon kale alongside. Garnish with grapes and serve.
- Also called culinary lavender buds; available at some supermarkets and farmers' markets, at many natural foods stores, and from .