Sheep's Tongues, Ecarlate with Spinach

Have several sheep's tongues; prick them with a trussing needle, and rub over with a little powdered saltpetre; keep them in a cool place until the following day; then prepare a brine of salt water, stir it to dissolve the salt, having enough of it to enable a potato to float on the surface. Lay the tongues in an earthen crock, pour the salted water over, and a few days after when sufficiently red, soak them for twelve hours, and then blanch in plenty of water. Braise the tongues in a mirepoix stock (No. 419) moistened with white wine, and let boil; when cooked set them under a weight, pare and keep warm; dress and garnish with cooked spinach (No. 2820). Serve a half-glaze sauce (No. 413) apart.