Italian Shellfish Stew

Name: Italian Shellfish Stew
Ingredients: 2 Tbs. extra-virgin olive oil; 1 large yellow onion, chopped; 1 garlic clove, minced, plus 2 garlic cloves, halved lengthwise; 8 plum tomatoes, halved lengthwise, seeded and diced; 1/4 tsp. red pepper flakes; 1/2 cup (4 fl. oz./125 ml) tomato sauce; 1/2 cup (4 fl. oz./125 ml) dry red wine; 3/4 lb. (375 g) cleaned squid, tentacles trimmed, bodies cut in 1/2-inch (12-mm) rings; 3/4 lb. (375 g) firm white fish fillet, cut into 3/4-inch (2-cm) pieces; 1/2 lb. (250 g) sea scallops, side muscle removed, scallops halved horizontally; 1/4 lb. (125 g) shrimp, peeled and deveined; 12 littleneck clams, well scrubbed; 4 slices coarse country whole-wheat bread, each about 1 inch (2.5 cm) thick, toasted; Chopped fresh flat-leaf parsley for garnish