Cut the daikon radish into 2 cm thick round, then cut in half or quarters. You can round the edges if you prefer.
In a pan, add a little salt (not listed) and water, and boil the daikon radish. Add the daikon radish before boiling. It should be cooked and translucent in about 20 minutes. It is better to boil in the water leftover from rinsing rice.
This prep is very important for the taste to penetrate into the daikon radish. While the daikon radish is boiling, prepare the squid by removing the guts and the cartilage, then cut into appropriately sized pieces.
Add water, dashi stock granules, squid, sugar and sake into the pan from Step 2. Skim off the scum until it comes to a boil, about 5 minutes.
Add soy sauce and mirin and put on a small lid or a piece of aluminum foil that sits right on top of it, and simmer over low heat for 15-20 minutes. (The taste penetrates the daikon radish as it cools).
Calculate the cooking time including the cooling time, before cooking. You would like to cool it for at least 30 minutes. Flip the daikon radish over around halfway through cooling.
Warm it up before serving and enjoy. You can add and simmer the tentacles with it, deep fry, or toss into a salad.
Story Behind this Recipe
I heard from a TV program that squid will turn out tender if you add it to water before boiling.
So when making my "simmered daikon radish with squid" recipe I added the squid before boiling, and it came out very tender.
Other than prepping the daikon radish and adding the squid and the seasonings before boiling, this is my original recipe.
Add the squid before boiling. Refer to the "Story Behind this Recipe".
The squid will be tough and chewy if you cook it over high heat for a long time. The taste penetrates into the daikon radish while cooling off, so cook it for 15-20 minutes, cool it off and warm it up again before serving.
If you prefer a strong taste, adjust it by adding more mentsuyu.