How do I clean off bread stuck to a non-flat / patterened cast iron pan?
You should not use metal on cast iron or may damage the seasoning. It is best to clean it while still hot with a brush to get into the grooves and never use dish soap. Some coarse salt can help get rid of burnt on areas. Then reheat and coat with a bit of oil to protect the coating/seasoning. Patterned cast iron is difficult to season and may take more time developing a good seasoning.