Best Cioppino

Heat olive oil in a heavy large Dutch oven or large pot over medium-high heat; cook and stir onion until translucent, about 5 minutes. Add garlic to onion; cook until garlic is fragrant, about 2 minutes. Stir 1/4 cup parsley, basil, oregano, red pepper flakes, and bay leaf into onion mixture; cook and stir until fragrant, about 1 minute. Add wine to seasoned onion mixture; bring to a boil. Cook and stir mixture until most of liquid evaporates, about 10 minutes. Pour tomatoes with juice and fish stock into seasoned onion-wine mixture; simmer until flavors blend, about 15 minutes. Season with salt and pepper. Stir mussels into tomato mixture; cover Dutch oven with a lid and simmer for about 2 minutes. Add clams to mixture; simmer about 2 more minutes. Add halibut, scallops, and crab legs to mussels-clams mixture; cover Dutch oven and simmer until mussels and clams break open and halibut and scallops are cooked through, about 2 more minutes. Add shrimp to cioppino and cook until heated through, 1 to 2 minutes. Discard any mussels or clams that didn't open. Divide cioppino among serving bowls; sprinkle with 2 tablespoons parsley.