A while back I was making Tonkotsu, I already had some shio tare I made from some weeks before which I planned on using, but upon opening it I got an instant bang of funk and knew it had turned and was unusable. As a backup I had some shoyu tare which I was reluctant to use as I like to keep the tonkotsu as white as possible. For one it turned the soup a nasty color and the shoyu tare just didnt pair well with a tonkotsu. After that bowl I was left feeling really disappointed and wanted to try again and fix it.
So I sat down and tried come up with something new, a tare specifically to be used with tonkotsu, something that will enhance the pork flavor because for me tonkotsu is all about the pork. What I came with was just a mix of things taken from other recipes I have tried, but it worked so well and will definitely be my go to when making tonkotsu. Its very pork forward, using tonkotsu as a base and reducing it a lot, another ingredient that worked quite well was white pepper, it goes great with the pork and gives a nice little kick. Other than that the other ingredients were used to give an extra boost of umami and round out the flavor. I do use MSG in this, I have no problem with it, you could use kombu if you wanted instead, but I didnt want any briny flavor in this tare.
Put tonkotsu, sake, mirin and pork belly into a pot, simmer until the alcohol has cooked off.
Then add everything else except the white pepper and shiitake. Keep it simmering until its almost reduced by half.
Finally add the white pepper and shiitake and simmer until you are left with about 500 ml of liquid. Take it off the heat and let the everything sit for about 30 mins.
Strain with a fine mesh sieve. I put it in a container and freeze it and take it out when needed.
This makes me approx 15 servings. Use 30 - 35 ml per 300 ml of tonkotsu broth.
Play with the amount of tare yourself, this is my preference.