Combine the rice with equal amounts water and cook according to directions on package set aside.
Heat the oil in a large pot over medium heat. Add the leeks or onions and cook until tender (about 5 minutes). Add garlic and fennel seeds and continue cooking for another minute. Add the wine and cook over high heat until about half has been absorbed. Stir in tomatoes, salt and red pepper.
Bring the tomato mixture to a boil. Add the mussels, cover and steam over high heat, shaking the pot occasionally, until the mussels open, 3 to 5 minutes. Reduce the heat slightly, push the mussels aside and submerge shrimp in the liquid. Cook until the shrimp are uniformly cooked, 1 to 2 minutes. Adjust seasonings to taste.
To serve transfer the rice with a slotted spoon among four large, shallow, individual soup bowls. Ladle the mussels (discard ANY unopened ones, shrimp and broth on top. Garnish with parsley. Serve immediately.