02Meanwhile, melt the butter in another large heavy-bottomed pot over medium heat. Add the onions, leek, carrots, garlic, saffron, 2 teaspoons salt, and 1 teaspoon pepper and saute, stirring occasionally, for 5 minutes. Reduce the heat to low, cover, and cook for 20 minutes. Add the tomatoes and cook for another minute.03Add 2 cups of the reserved cooking liquid (discard the rest) and the rest of the wine, bring to a boil, lower the heat, and simmer uncovered for 5 minutes. Add the reserved mussels, the half-and-half, and the cream. Heat until just heated through but not boiling. Stir in the parsley or dill, 1 teaspoon salt, and 1/2 teaspoon pepper. Serve hot.