Indian-Spiced Sturgeon with Mint Yogurt Sauce

INGREDIENTS
1 teaspoon fennel seeds, toasted
2 cups plain yogurt (16 oz)
1 garlic clove, minced
1 teaspoon minced peeled fresh ginger
1/2 teaspoon ground cumin
1/2 teaspoon ground coriander
1/4 teaspoon black pepper
1/4 teaspoon turmeric
1/8 teaspoon cayenne, or to taste
1 teaspoon salt
6 (1-inch-thick) pieces skinless sturgeon fillet 6 oz each)
3 tablespoons finely chopped fresh mint
1/2 teaspoon finely grated fresh lemon zest

METHOD
Finely grind fennel seeds in grinder. Whisk together fennel and 1 cup yogurt with garlic, ginger, cumin, coriander, black pepper, turmeric, cayenne, and 1/2 teaspoon salt. Coat fish with yogurt mixture and marinate in a shallow baking dish, covered and chilled, 1 hour.

While fish is marinating, whisk together remaining cup yogurt, mint, zest, and remaining 1/2 teaspoon salt to make sauce.

Prepare grill for cooking.

Lift fish out of marinade, letting excess drip off (discard marinade), and grill fish, covered only if using a gas grill, on lightly oiled grill rack, turning over once, until just cooked through, about 12 minutes total. Serve fish with sauce.