MAKE THE GRANO: Cook the onion in the olive oil until translucent , about 5 minutes. Add the Grano and 12 cups water, salted as you would for pasta. Bring to a boil, then reduce heat to medium. Simmer, stirring frequently, until Grano is tender but still chewy, about 30-35 minutes. Drain well..
MAKE THE SALAD: Soak the cockles in water to cover with 1 tablespoon of salt for 30 minutes; drain and rinse. Heat 2 tablespoons of the olive oil; add the mussels, cockles, and ð cup of the wine; simmer until the shellfish open and then shell half into a bowl.
Bring a pot of water to a boil. Add salt, the sliced lemon, and the remaining wine. Poach the sea bass, scallops, salmon, and tuna for 4 minutes; remove with a slotted spoon; add to the clams and mussels. Stir in the Grano, string beans, parlsey, lemon juice, remaining olive oil, salt, and pepper. Serve over the frisée on a platter.
Adapted from recipe in La Cucina Italiana, February 29, 2000.