Crayfish Soup

Name: Crayfish Soup
Cuisine: European
Ingredients: 3 3⁄4 lb. live crayfish, rinsed; 2 tbsp. canola oil; 1⁄2 cup cognac; 2 stalks celery, chopped; 1 medium carrot, peeled and chopped; 6 cloves garlic, peeled and finely chopped; 2 tbsp. tomato paste; 7 cups fish stock; 5 sprigs fresh thyme; 3 bay leaves; 1 1⁄2 tsp. arrowroot; 1 cup creme fraiche; Salt and freshly ground black pepper; 2 tbsp. finely chopped fresh chives