A retort container comprising: a container body constructed substantially of thermoplastic and having a side wall extending about a container body axis, the side wall having a lower end and an upper end, the upper end defining an upper edge that extends about a top opening of the container body, the side wall having an inner surface and an outer surface; a metal end closing the top opening of the container body, the metal end having at least a metal layer and comprising a central portion and an outer peripheral portion extending generally radially outwardly from the central portion and extending circumferentially about the central portion, the peripheral portion having a radially outer part and a radially inner part, a first heat-sealable material being present on one of (a) a lower surface of at least the peripheral portion of the metal end and (b) the inner surface of the side wall adjacent the upper end thereof, the radially outer part of the peripheral portion defining a curl, the radially inner part of the peripheral portion defining a chuck wall that extends generally downward from the curl and has a radially outer surface forming an interface with the inner surface of the side wall of the container body; a seam connecting the metal end to the upper end of the side wall, the seam having the curl of the metal end and the upper end of the side wall interlocked; the interface between the chuck wall and the side wall being fused by heat-sealing of the first heat-sealable material between the radially outer surface of the chuck wall and the inner surface of the side wall, the interface being oriented along a direction such that stress on the interface caused by internal pressure inside the container exerted on the metal end is predominantly shear stress, characterised in that the interlock takes place via a biting interface between a folded peripheral edge of the curl and the side wall. a container body constructed substantially of thermoplastic and having a side wall extending about a container body axis, the side wall having a lower end and an upper end, the upper end defining an upper edge that extends about a top opening of the container body, the side wall having an inner surface and an outer surface; a metal end closing the top opening of the container body, the metal end having at least a metal layer and comprising a central portion and an outer peripheral portion extending generally radially outwardly from the central portion and extending circumferentially about the central portion, the peripheral portion having a radially outer part and a radially inner part, a first heat-sealable material being present on one of (a) a lower surface of at least the peripheral portion of the metal end and (b) the inner surface of the side wall adjacent the upper end thereof, the radially outer part of the peripheral portion defining a curl, the radially inner part of the peripheral portion defining a chuck wall that extends generally downward from the curl and has a radially outer surface forming an interface with the inner surface of the side wall of the container body; a seam connecting the metal end to the upper end of the side wall, the seam having the curl of the metal end and the upper end of the side wall interlocked; the interface between the chuck wall and the side wall being fused by heat-sealing of the first heat-sealable material between the radially outer surface of the chuck wall and the inner surface of the side wall, the interface being oriented along a direction such that stress on the interface caused by internal pressure inside the container exerted on the metal end is predominantly shear stress, characterised in that the interlock takes place via a biting interface between a folded peripheral edge of the curl and the side wall.