Was it an genuine Bundeswehr EPa entree for sure?!
This "EPa" read-to-serve-meals were also avialable in the supermarkets, even the square containers. Maybe you´ve got one of these? They had a printed on a card board label glued on top, instead the stamped big letters.
I'm almost sure it was original; square container, inscriptions(military style) stamped in the metal lid...
There was also a rice pudding, a margarine tube, several pâté containers...