First you'll need to tenderize the octopus. Boil a large pot of salty water. Cook the octopus for 2 minutes, then remove to a cutting board. While the octos are cooling turn the oven to 225°F.
Line a heavy, lidded pot with the parsley, fennel fronds, oregano, green onions and bay leaves. Trim fatty bits from the octopus and clean out the heads (normally this last step has been done for you, but not always). Cut the octopi into large pieces and nestle into the pot of greens. Cover the pot and cook for 90 minutes to 4 hours, depending on how large and tough the octopi are. I typically shoot for 2 hours. Don't worry about the lack of liquid in the pot: The octos will release enough to make a flavorful broth.
When the octopus is tender, remove from the pot and cut into serving-sized pieces. Coat with some of the olive oil and either grill or broil until you get some char marks, about 8 to 10 minutes.
Toss the octopus with the rest of the olive oil, garlic, the paprika, smoked paprika and cayenne. Add salt and black pepper to taste and serve with lemon wedges, at room temperature or slightly warm. Serve with bread.