Either pull the octopus out within a minute or simmer it over 40 — everything in between is the toughest it gets.
3 servings60 min
Clean and rinse the octopus. If it is frozen, use it as it is — freezing breaks up the tissue and it comes out more tender.
Bring a large pot of water to the boil and dip the legs in and out three times, holding them by the head. They curl and set their shape.
Lower the octopus in and simmer gently for 40–50 minutes, until a chopstick slides easily into a thick leg.
Turn off the heat and leave it in the cooking water for 20 minutes to cool. Lifting it out to cool makes it shrink and toughen.
Meanwhile cut the potatoes into large pieces, skin on, and boil them in salted water for 15 minutes — a fork should go in without them collapsing.
Slice the cooled octopus on the diagonal, 1 cm thick.
Slice the garlic thinly and cook it in the olive oil over low heat for 2 minutes to perfume it. Stop before it browns.
Toss the warm potatoes with the octopus, the garlic oil, lemon juice, paprika and salt — gently — and scatter the parsley over.
The cooking time is where this dish is decided. Octopus muscle is bound by collagen-rich connective tissue. At 30–60 seconds the proteins have not yet contracted, so it is tender; past 40 minutes the collagen has melted into gelatin and it turns tender again. In between is the toughest window — the proteins have contracted but the collagen has not yet dissolved.
Dipping the legs three times is for the shape: the sudden heat shrinks the skin and curls them.
Cooling it in its own water is about shrinkage too. Lift hot octopus into cool air and the muscle fibres tighten fast.
Frozen octopus is actually more tender. Growing ice crystals physically break the muscle tissue. There is no reason to insist on fresh.
On the numbers: 500 g of octopus is about 410 kcal raw, with 75 g of protein and 5 g of fat, before the potato and oil. Vitamin B12 comes to around 100 µg, though absorption from a single meal saturates near 2 µg.
You can set the cholesterol worry aside. Octopus holds 48 mg per 100 g — a quarter of one egg (186 mg), and nothing like squid (233 mg).
Dress it warm. Warm potatoes drink up the olive oil and lemon juice.
Boil the potatoes in their skins. The less cut surface under water, the less they fall apart.
Seafood
Moderate evidence100 g holds 82 kcal, 14.9 g of protein and only 1.04 g of fat, with 20.0 µg of vitamin B12 (833% of the requirement), 44.8 µg of selenium and 5.3 mg of iron. The old warning about cholesterol does not survive contact with the randomised evidence on dietary cholesterol.
Vegetables
Moderate evidenceTotal potato intake showed no association with type 2 diabetes risk. Only fried potato did, at a hazard ratio of 1.12.
Oils & fats
Strong evidenceCardiovascular events were 31 % lower in a randomised trial of 7,447 people. Against other vegetable oils, though, there was no difference.
Vegetables
Moderate evidenceThe evidence for garlic points to a modest drop in blood pressure and cholesterol. The trick is to crush it and wait ten minutes before it hits the heat.