For best results, use firm, ripe plums that hold their shape when sliced.
If fresh ground almonds are not available, you can pulse high-quality almond meal in a food processor, but ensure it is very fine to avoid a gritty texture.
This tart can be stored at room temperature for up to 2 days, covered loosely with plastic wrap.
Substitute apricot jam or peach preserves for the currant jelly if preferred.