AGA Yorkshire Pudding & Muffin Tray by Portmeirion.
The Portmeirion fire and ice vitreous porcelain is one of the best in the industry.
The oven-to-tableware goes through three firings, the first is a biscuit firing at 1200 degrees C, the second is the glaze firing at 1140 degrees C and finally the lithography takes place to add the decoration before its final firing at 1100 degrees C.