This is one of my favourite things year round, served lukewarm in winter or at room temperature in summer.
Octopus meat is beautifully tender when properly cooked. It has a very mild sweet-savoury flavour which some compare to chicken and some to squid though neither comparison really stands up in my view. Perhaps crab or scallop come closer. When well prepared, it really is very easy to like. Its flavour is mild, unless you cook it with its own ink, it has a nice mouth feel and is very easy to eat: no bones, no shells, no debris. It is also very healthy eating. It is a low calorie, high protein, low fat, low carb, zero-sugar food. It is rich in anti-oxidant selenium and very high in iron, B vitamins and zinc. On the down side it is high in sodium and cholesterol - not a problem for most people, but you may have a specific medical reason for forgoing this delicacy.
When I was growing up in Malta it was common summer sport for the boys to tickle octopi out of their hiding places using a fork, stringing up them up in a row on a fishing rod or bamboo pole to proudly take home for Mum to cook. To soften up the flesh, which would otherwise be very tough, they would beat and beat the octopus on the rocks, a common practice round the Mediterranean. Otherwise at home you would need to beat with a steak hammer for about 10 minutes, a long and potentially messy job. You don't have to do this if you freeze a fresh octopus overnight and cook from frozen. Or buy frozen or just defrosted. Frozen is good for octopus: the flavour is not impaired at all, the flesh tenderizes much more quickly and the octopus comes ready prepared and cleaned.
I have two ways of preparing octopus, both simplicity itself. One is the classic Italian way and the other is what I call the Greek way because learnt it from my friend Eleftheria. The Italian way is to cook your defrosted or very well beaten octopus in a pan of boiling water along with a red wine cork or two. The theory is the traces of tannin or else a particular enzyme found in the cork help to tenderize it. I doubt this is true but as I'm never without a red wine cork or two, I do put one in, a kind of superstition! I don't do the popping in and out of the water three times though, another Italian practice that claims to make octopus become tender faster.
So what you do is bring a large pot of water to the boil and then lower the octopus into the pot so that it is submerged and totally covered. Turn the heat down and simmer a defrosted octopus for 40 to 60 minutes or until tender - calculate about 20 minutes for every 500g ( 1.1 pounds) . Test as if it were a baked potato: a wooden toothpick or skewer should pierce it and go through easily without encountering any resistance. Finally - and this is important for a truly tender octopus - leave it to cool down slowly in the pot covered in the cooking liquid. I usually add fresh bay leaves or a piece of cinnamon stick to the cooking water to keep fishy aromas to a minimum rather than for flavouring purposes. This time I tired a small star anise, and loved it.
The "Greek" style, which may or may not be typically Greek is even more straight forward. Just choose a heavy bottomed pan with a tight fitting lid, pop the octopus in, cover, place on the lowest possible heat and leave till done, calculating timing as before. The octopus braises and steams gently taking on a splendid purple hue from the head to the tip of its tightly curled tentacles, as you can see in my photo. As it loses its water it shrinks and cooks to supreme tenderness. It is ready when it has re-absorbed the liquid it released, but don't cook too long as left too long the octopus can end up dried up or worse, burnt and stuck to the pot. The drawback with this method is that the octopus remains pretty salty. What I usually do is stay Greek and make grilled octopus. I cut the cooked octopus up into small pieces without rubbing off the skin or suckers and grill it gently on a hot cast iron ridged grill pan till the outside is lightly charred with crispy bits, then drizzle with best EVO oil when done. This way I end up with pre-salted octopus pieces that are crisped on the outside and tender on the inside, just sublime! Otherwise I add the chopped octopus pieces to a tomato sauce and serve it on an on unsalted creamy polenta, putting the octopus' saltiness to good use in seasoning the polenta.
Because octopus has such a delicate flavour, the Italian instinct is to avoid adding sauces, dressings or extraneous flavours with would mask and overpower the octopus' own subtle taste. Potatoes and polenta are perfect partners that act as a gentle background to bring it out and show it off, for the octopus is inevitably the protagonist of the dish it features in. The popular Polipo con Patate "salad" is, as far as I know, made everywhere along Italy's 7,600 kilometer coastline (over 4, 700 miles). So far once here is a recipe for a dish that is national, an Italian dish not one from one of Italy's regional cuisines.