Vintage enamelware roasting pan, black and blue. It's porcelain enamel over steel, about 18" x 12" x 8" overall (pan and lid each about 4" deep).
It's about 1920s vintage, showing age and wear after almost 100 years of use. This has some soil, and spots of enamel loss. It would make a fine piece for use or display with a little bit of cleaning!