Start with the Octopus:
Heat 2 tablespoons of the olive oil in a pan to medium high heat. Add the cleaned octopus and let cook without stirring for 3 minutes. Turn and cook 3 more minutes. Remove and hold temporarily. Add the other 2 tablespoons of olive oil, then add the celery, onion and bay leaves. Sauté until the celery and onion are soft. Add the white wine and cook for 3 minutes. Add the tomatoes and the octopus and bring to a simmer. Cook at a low simmer for 1 hour or until the octopus is very tender.
In the meantime, for the Main Stock:
Heat the olive oil in a pan to medium. Add the Linguica and onions and cook until the sausage is rendering off fat and slightly browning. Add the green chili and potatoes and toss.
Add the white wine and cook for 3 minutes. Add the tomato, kale, clam juice, chicken stock, the octopus and its sauce. Bring to a boil, then reduce to a simmer. Simmer for 15 to 20 minutesa till the potatoes are soft.
Add the seafood and simmer until the fish and shrimp are done and the clams are open. Serve with Artisan crostini.