Author Notes: Octopus and potato salad is a favorite dish all along the Italian coast.
You can find it in practically every Tuscan and Ligurian port. Cleaning the octopus involves removing the eyes, beak, and innards, and rinsing under cold water—this is often already done when bought from a fishmonger or at a supermarket or if you have bought it frozen, but at my fresh-off-the-boat fisherman’s shop front, they are just as they were pulled out of the water. 

Octopus and Potato Salad 

Serves: 4 as an entrée

Ingredients

• 2pounds (1 kg) octopus, cleaned
• 2medium-large potatoes, washed but unpeeled
• 1/2cup (125 ml) dry white wine
• Handful of parsley leaves, chopped finely
• Juice of 1 lemon
• 1/4cup extra-virgin olive oil
• 1stick of celery, thinly sliced (optional)
• Salt and freshly ground black pepper to taste

Directions

1. The day before planning to cook the octopus, put it in the freezer to freeze completely. The next day, let it defrost before cooking.
2. Place the potatoes whole and unpeeled in a pot of cold water and bring to the boil. Cook until tender (a knife should slip through it easily), about 20 minutes. Drain and let cool before peeling and chopping into 1/2-inch cubes. Set aside.
3. Heat a heavy-bottomed pot or casserole dish over high heat. Add half the olive oil and brown the whole octopus in the pot, a few minutes. Pour over the white wine and cover. Turn flame down to lowest heat available and let simmer about 45 minutes (or until very tender—poke it with a fork to check and if not yet tender enough, leave it for a little longer) and let it cool in the pot until tepid. Remove, saving the liquid (as it is delicious), drain on paper towels, and when cool enough to handle, peel off the skin by gently rubbing with your fingers (baby octopus won't need this treatment) and chop into pieces about 2 inches (5 cm) long.
4. Toss the octopus and potatoes together with the parsley, lemon juice, the rest of the olive oil, and the thinly sliced celery. Add a spoonful or more of the pan juices and salt and freshly ground pepper to taste (it's usually already quite flavorful). Eat at room temperature or chilled.

https://food52.com/recipes/59736-octopus-and-potato-salad-insalata-di-polpo-e-patate