Large Studio Art Pottery Blue Green Glazed Dish Ashtray Open Mouth Frog & Leaf

This is a nice solid piece- well made and almost feels like some type of stone. Took closeups for a better way to describe this one-of-a-kind item. Frog and leaf attached to the dish and all nicely glazed and hand crafted. See all images for more info and details. Signed with initials on bottom...I think it's SB. Some residue along back rim that I tried to show in pics.