Rinse quinoas; drain well. Bring quinoas and water to boil in small saucepan on medium-high heat. Reduce heat to low; cover and simmer 13 minutes or until liquid is absorbed, stirring occasionally. Spread cooked quinoa on baking sheet to cool. Stir in 1/4 cup of the hazelnuts. Set aside.
Preheat oven to 450°F. Brush racks of lamb lightly with 1 teaspoon of the oil. Sprinkle with 1 teaspoon of the sea salt and pepper. Coat lamb with quinoa mixture, pressing firmly to adhere. Place lamb on roasting rack in foil-lined shallow roasting pan. Drizzle with 2 teaspoons of the remaining oil.
Roast 20 to 25 minutes or until desired doneness.
Meanwhile, for the Mint Pesto, mix remaining 2 tablespoons oil, remaining 1 tablespoon hazelnuts, lemon juice, mint, garlic powder and remaining 1/8 teaspoon sea salt in small bowl until well blended. Stir 1 teaspoon of the pesto into yogurt. To serve, carve lamb into chops. Drizzle with remaining pesto. Serve with yogurt sauce.