In a large pot or Dutch oven such as Le Creuset, heat the olive oil over medium heat. Add the onions and cook over medium-low heat for 5-10 minutes, stirring occasionally, until golden brown. Add the garlic and cook for 1 more minute. Stir in the chicken stock, tomatoes, saffron, 1 tablespoon salt, and 1 teaspoon pepper. Bring the soup to a boil, then lower the heat and simmer for 15 minutes.
Meanwhile, fill a medium pot with water, add 2 teaspoons salt, and bring to a boil. Add the orzo and cook for 7 minutes. (It will -finish cooking in the soup.) Drain the orzo and add it to the soup. Stir in the cream, return the soup to a simmer, and cook for 10 more minutes, stirring frequently.
Serve hot with Grilled Cheese Croutons scattered on top.