Heat the olive oil in a medium saucepan over high heat until hot. Add the garlic and
half the chopped scallions. Lower the heat and cook until golden.
Add the tomatoes, tomato paste, red wine, lemon zest, thyme, salt and pepper.
Cook over medium heat for about 10 minutes, stirring occasionally.
Add mussels to the tomato sauce and continue to cook until you see them open, about 3 minutes. Add the shrimp and calamari to the tomato sauce and cook for 2 minutes only or until they are opaque all the way through.
Serve the ragout (stew) with hot crusty bread or as a sauce for pasta. Sprinkle with the rest of the chopped scallions and parsley.