A method of producing a clad metal ingot suitable for rolling to form a clad metal sheet, and the clad metal ingot so produced. The method involves providing a solid core ingot having an upper side with a rolling face thereon having cavities extending inwardly into the ingot from the rolling face. All or all-but-one of the cavities are blocked against molten metal entry and casting cores extending outwardly from the rolling surface are provided in alignment with the cavities. Molten cladding metal is cast on the rolling face around the casting cores to produce a composite ingot and the casting cores are removed to produce voids in the cladding layer, and the cavities are unblocked. The resulting interconnected cavities and voids are filled with a molten metal to form cast-in-place metal lugs keying or pinning the cladding layer to the core ingot.