Combine the tomatoes, basil leaves, garlic, olive oil salt and red pepper, and let them sit for at least a half hour.
While they're sitting, combine 6 cups water, salted as you would for pasta, and Grano in a pot. 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.
Stir the Grano into the tomatoes, add the olives, check seasoning, and serve.