How to Make It
Rinse grape leaves under cold water; place in a large bowl. Cover leaves with cold water; let stand for 15 minutes. Drain and carefully separate grape leaves. Remove and discard stems.
Place leaves in a large saucepan, and add chicken stock, making sure leaves are covered with stock. Bring to a simmer over medium. Cover and cook until tender, 15 to 20 minutes. Drain and set aside to cool completely.
Gently stir together tuna, couscous, onion, garlic, serrano, parsley, mint, lime juice, curry powder, salt, and olive oil in a large bowl.
Place grape leaves, vein side up, on a work surface. Spoon 1 to 1 1/2 tablespoons of the tuna mixture (depending on the size of the leaf) on the center of the bottom half of each leaf. Fold up the stem end of the leaf to cover the mixture; fold in sides, and roll up tightly.
Place dolmas on a platter, and cover with plastic wrap. Refrigerate for 2 hours and up to 8 hours. Serve cold or at room temperature with Citrus-Yogurt Sauce.