This is based on my wife's suggestion. This is a variation on the theme of "Kurosu-ni" 黒酢煮. Some time ago, I decided to preserve the simmering liquid by removing the congealed fat and straining it after each use. I adjust the seasoning by adding more black vinegar, soy sauce and mirin. Sometimes I also add water to compensate for evaporation. The simmering liquid became rich in taste and collagen and it congeals like jelly in the refrigerator. Since the simmering liquid has become a rather large amount, at my wife’s suggestion, I cooked a whole Cornish game hen stuffed with very small Yukon gold potatoes (or “potatolets”).
When I simmer various chicken parts in this mixture of black vinegar, mirin and soy sauce, I often cook root vegetable such as potato, nagaimo, and daikon. Potato can be a problem since a part of it can dissolve into the simmering liquid making it more difficult to strain. Since we found small potatolets (the second picture below in the left), I decided to use them with the skin-on which prevents the potatoes from breaking up and dissolving.
I first stuffed the cavity of the bird with the potatolets and trussed the chicken in my usual way (leaving string long so that I can fish it out later more easily. This was not needed however--in the picture below left). I poured in the simmering liquid. Although the depth of the liquid was enough to completely submerge the chicken, the chicken floated up (in the picture below on the right). I used a silicon “otoshibuta” to keep it submerged and simmered it for 1 hours then let it cool down in the liquid. We did not eat this immediately. I put it in the refrigerator. The next day, I skimmed off the congealed fat that had formed on the surface but not much fat was present. I warmed it up on simmer for another hour.
I removed the chicken and trusses as well as the potatolets (in the picture above on the right).
The Cornish game hen was tender and the meat fell off the bones. The potetolets kept their shape but were soft and could easily be mashed to soak up the simmering liquid. The skin was also soft. This is a interesting way to cook and serve whole Cornish game hen.