First, let's prepare the boiled octopus. This is Mizudako, giant Pacific octopus from Hokkaido. Huge, isn't it? It's almost the size of my arm.
The arm of the octopus is very thick so cut it in half lengthwise.
Begin slicing the octopus at 3 mm (0.1”) intervals, leaving the piece attached with the initial cut and then removing it with the next cut as shown.
Make a deep incision and cut out the slices alternatively. Making deep cuts in the octopus makes it easy to enjoy the chewy texture.
Place the octopus onto a tray. Then, add the sake and toss to coat. If sake isn't available, you can leave it out.
Dice the tomato into 2 cm (0.8") pieces, and slice the zucchini into 5 mm (0.2") thick half-moons.
Now, let's cook the pasta. Add the 0.7 to 1 percent salt to the pot of hot water, and bring it to a boil. When you use a small pot, gradually submerge the spaghetti in the water as it softens.
Cook the pasta for 1 minute shorter than the time described on the package.
And now, heat a pan and add the olive oil. Swirl the pan to coat it with the oil. Add the zucchini.
When they are browned, flip the slices over.
Turn the heat to low, and add the chopped garlic and dried red chili pepper. Stir-fry them until aromatic.
Then, add the diced tomato.
The tomato contains lots of water so stir fry and reduce the liquid. Now, lightly season it with salt. You should go easy on the salt since the boiled octopus also contains salt. Reduce the liquid to give it a slightly thick consistency.
Test a string of pasta to check the firmness.
When the pasta is almost ready, add the boiled octopus to the pan. Add the soy sauce and butter.
Lightly stir the ingredients and reduce to the lowest possible heat.
Now, place the pasta into a mesh strainer. If you are a cooking novice, we recommend beginning to cook the pasta when the sauce is ready to avoid overcooking.
Then, add the pasta to the pan.
Quickly coat the noodles with the sauce. Now, it is ready.
Using tongs, arrange the spaghetti on the plate along with the ingredients to make the dish visually appealing.
Finally, sprinkle on the coarsely ground black pepper, grated Parmesan cheese, and chopped parsley leaves.
The more you cook the octopus, the tougher and smaller it becomes, so just warm the octopus and be sure not to overcook it.
When the olive oil and the cooking water with the pasta are emulsified, the sauce becomes thick. This will help the spaghetti hold more sauce and make the dish more delicious.