For the cioppino: Heat the olive oil in a large pot and saute the onions until transparent. Add the garlic and saute until it begins to brown. If available, stir in crab butter and let cook slowly for 5 minutes (crab butter is saffron yellow in color and adds a distinctive rich flavor). Pour in the wine to keep the butter and garlic from burning. Add the tomato sauce, tomatoes and red pepper flakes and simmer for about 15 minutes.
Add the broth, crabs with their liquid and roe and some salt and black pepper. Cover and continue to simmer over low heat for about 8 minutes. Add the clams, mussels and prawns and cook for 2 more minutes. Serve in a bowl and sprinkle with fresh parsley.
This recipe was provided by a chef, restaurant or culinary professional and makes a large quantity. The Food Network Kitchens have not tested it for home use and therefore cannot make any representation as to the results.