This pretty 10-1/2" soup plate is a black (or sepia) transferware design with hand enameled plants and flowers in the Chinoiserie style. The pattern name is marked on the back: Indian Plants. The pattern can be seen at the Transferware Collectors Club database.
It was made at the rather obscure Staffordshire Pottery of Zachariah Boyle between 1823 and 1828. See Godden's mark 522. After that date, "& Sons" was added to the mark. Hand painted in green are the (pattern?) numbers 12 and 909. The initials "Z.B." and the type of body: "Celtic China", are also part of the mark.
The piece is in excellent condition. It is bright and shiny. There are no chips, no cracks, no crazing, and no repairs. It rings when tapped.