Notes: This is a streamlined version of chef Bert Cutino’s cioppino from the Monterey, California, restaurant he cofounded. Have the crabs cleaned and cracked at the seafood market. If desired, ask for the crab butter; press it through a fine strainer and stir it into the broth just before adding the fish in step 2.
Pour olive oil into a 5- to 6-quart pan over medium-high heat; when hot, add onion and garlic and stir often until onion is limp, 3 to 5 minutes. Add wine, tomatoes (with their juice if canned), tomato paste, basil, and pepper; bring mixture to a boil over high heat, then reduce heat and simmer, stirring often, for 10 minutes. Add salt to taste.
Meanwhile, rinse and drain fish, shrimp, scallops, and crab; cut fish into 1- to 2-inch pieces. Scrub clams. Gently stir fish, shrimp, scallops, and clams into tomato broth; cover and simmer just until fish, shrimp, and scallops are opaque but still moist-looking in center of thickest part (cut to test) and clams have popped open, 7 to 9 minutes. Discard any clams that don't open. Add crab and press gently to immerse in broth; cover and cook just until hot, 2 to 3 minutes.
Ladle cioppino into wide bowls and sprinkle with parsley. Serve with bread and lemon wedges.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.