A spicy preserve comprising a mixture of dried fruit, apple, suet and candied fruit and spices steeped in rum or brandy. It has been part of British cookery for centuries and did originally contain meat, though now the only meat present is in the suet.
It's the traditional filling for individual mince pies, served warm at Christmas, but can also be used to fill tarts, pastries or even pasta.
There are some excellent ready-made versions available (including ones made with vegetarian suet) but nothing beats homemade, and it's very simple to make.