A filling device comprises a modified vacuum-filling head that introduces a viscous filling, such as a gravy, into a loaf matrix in a retortable can so that the filling remains enclosed by the set loaf matrix after retorting. The filling can remain as a viscous gravy or can set as a gel, depending on the formulation of the filling. Preferably the viscous filling is distributed horizontally into the loaf matrix, for example through horizontally-facing apertures, during a pause in the descent of the can away from the filling device. The flow of the filling can be controlled by synchronized pneumatic valves.