BBQ Chicken with a Dijon Tarragon Sauce

This is a great, simple BBQ dish. Reall goes well with Grilled Potato Salad with Radicchio and a Sherry Vinaigrette

 CHICKEN

 1 tbs coriander seeds
1 tbsp yellow mustard seeds
2 tsp fennel seeds
3 tbs mild paprika
2 tsp ground black pepper
2 tsp kosher salt
8 large chicken breast halves with skin and bones

SAUCE

1/3cup Sherry wine vinegar
3 tbs Dijon mustard
2 cups olive oil
1/2 cup chopped fresh chives (about 2 large bunches)
3 tablespoons chopped fresh tarragon

CHICKEN:

Combine coriander seeds, mustard seeds, and fennel seeds in spice mill; grind finely. Transfer spices to small bowl; whisk in paprika, pepper, and 2 teaspoons salt. Sprinkle chicken lightly on both sides with salt, then generously with all of spice mixture. Arrange chicken on rimmed baking sheet. Let stand 1 hour or cover and chill up to 1 day.

SAUCE:

Whisk vinegar and mustard in medium bowl to blend. Gradually whisk in oil. Mix in chives and tarragon; season with salt and pepper.  Prepare barbecue (medium-high heat). Grill chicken, skin side down, until deep golden brown, about 5 minutes. Using tongs, turn chicken over. Cover barbecue and grill until chicken is cooked through, about 15 minutes. Spoon some sauce in center of each plate; top with chicken. Spoon more sauce over chicken. Serve, passing remaining sauce separately