Danbury Mint have issued a number of porcelain Celtic plates. To date 17 plates have been issued (that I know of).
Each plate is edged with 22 carot gold and comes with a numbered certificate of authenticity.
Below are images of the 17 plates (8.25 inches in diameter) from my own collection.
You can order new 3 in a row plate direct from Danbury Mint
on telephone order line 0845 218 8000
Also online using Danbury Mint web site www.danburymint.co.uk