Ingredients

3 tablespoons brown mustard seed

1 teaspoon fennel seed

2 teaspoons coriander seed

1 teaspoon cumin seed

1 teaspoon whole black peppercorns

2 teaspoons dried thyme

1 tablespoon dry mustard

1 teaspoon ground ginger

2 teaspoons coarse salt

1 teaspoon sugar

2 large Idaho potatoes (1 1/2 pounds), scrubbed

1 teaspoon extra-virgin olive oil

1 1/4 pounds pork tenderloin

2 tablespoons Dijon mustard

2 tablespoons dry white wine

One 14 1/2-ounce can low-sodium chicken stock, or homemade, skimmed of fat

1 tablespoon all-purpose flour

1/2 pint blackberries (about 5 ounces)

2 teaspoons chopped fresh thyme, for garnish

Vegetable-oil cooking spray

Preparation

Place mustard seed, fennel, coriander,cumin, and peppercorns in a dry skillet.Place over medium heat, moving skillet tokeep seeds from burning, until aromatic,about 2 minutes. Mustard seeds will beginto pop. Transfer seeds to a spice grinder,cool slightly, and pulse until finely choppedbut not powdery. Transfer mixture to a smallbowl, and stir in the thyme, dry mustard,ginger, 1 teaspoon salt, and sugar. Set aside.

Heat oven to 450 degrees. Position two racks inoven. Spray a small roasting pan and a largecookie sheet with cooking spray; set aside.

Cut potatoes into 1/3-inch-thick sticks. In abowl, toss with oil and 3 tablespoons spicemixture. Spread in a single layer on cookiesheet; bake on bottom rack 15 minutes.

Meanwhile, rub pork with 1 tablespoonDijon mustard. Sprinkle with 1/2 teaspoonsalt and 2 tablespoons spice mixture; patwith hands to make it stick. Lower oven to425 degrees; place pork in prepared pan. Place onupper rack in oven. Cook until fries aregolden and pork is cooked through (145 degrees internally), about 25 minutes. Transfer fries to a bowl and pork to a cutting board;cover both loosely with foil to keep warm.

Place roasting pan on stove over medium-highheat; stir in wine, scraping bottomof pan to release browned bits. Stir in stock;cook, stirring occasionally, until reducedby half, 5 to 7 minutes. Whisk together flourwith 1/4 cup water in a bowl; whisk intosimmering stock mixture. Whisk in remainingtablespoon Dijon mustard; cook untilmixture begins to thicken, 2 to 3 minutesmore. Stir in berries; cook until they beginto soften, about 2 minutes. Season frieswith remaining 1/2 teaspoon salt. Slicepork, and transfer to platter. Serve immediatelywith blackberry-mustard sauceand chopped thyme.