Freeze tofu for one night, cut into square pieces, and boil them to rid them of their bean-like smell. Add them to a mixture of chicken broth and extracts, ham extract, and pork extract and braise. When serving, remove the chicken and ham and the like, leaving only the shitake and the winter bamboo shoots.
When tofu has been braised for a long time its texture becomes spongy, with its surface becoming honey-combed like frozen tofu.1 For stir-frying use soft tofu, while braising should be done with firmer tofu.2 The household of Officer Jia Zhihua cooks tofu with mushrooms, even during the summer they follow the same recipe for frozen tofu, since it is very good. Do not use strong flavoured hun meat broths3 for this dish since doing so would destroy to delicate light flavours of this dish.
1I think Yuan Mei is trying to say normal tofu looking like frozen tofu after prolonged boiling.
2This feels slightly off on a tangent, and may not apply exclusively to frozen tofu. In fact, the rest of the paragraph goes on a tangent.
3Though the term hun 葷 (pronounced hoon) is commonly used to refer to any meat from any animal, this is clearly not the meaning here. When Yuan Mei say’s “葷湯”, or “hun soup”, he is not saying “animal broth” since there is already chicken and ham used to make this dish. Most likely he is referring to the stronger and richer tasting pork, and possibly beef broth, thus I translating it as such. It seems that every “vegetable” dish here is full of animal ingredients. This is still true for most Chinese vegetable dishes where lard and broth (or MSG) are “musts”.