2 tablespoons (1/4 stick) butter
2 large leeks (white and pale green parts only), thinly sliced

4 dozen mussels, scrubbed, debearded
1 cup dry white wine
8 fresh parsley sprigs
10 saffron threads, crushed
1/2 cup whipping cream
2 tablespoons minced fresh parsley

Melt butter in heavy large deep skillet over medium-low heat . Add leeks and sauté until tender, about 8 minutes.

Combine mussels, wine and parsley sprigs in large Dutch oven. Cover and cook over high heat until mussels open, about 6 minutes. Using tongs, transfer mussels to large bowl, discarding any that do not open. Strain mussel juices into skillet containing leeks. Add saffron and cream to skillet; boil until reduced to sauce consistency, about 2 minutes. Stir in minced parsley. Season with salt and pepper. Add mussels and any accumulated juices to skillet. Stir over medium heat until heated through, about 2 minutes. Divide mussels among 4 bowls; pour sauce over.