I first made this conserve with Satsuma plums. These have a dark, solid red skin and a dark red flesh, giving a rich color to the jam. Other dark fleshed plums (e.g. Elephant Heart, Black Beauty) also work well with this recipe.
3 lbs plums (dark fleshed plums preferred)
3 lbs sugar
1/2 lb raisins
1/2 lb broken walnuts (less is OK)
2-3 oranges, relatively thin-skinned (i.e. not Naval oranges)
Wash and mince, grate or grind oranges, reserving juice and discarding seeds.
Remove stones from plums and cut into quarters.
Combine oranges, plums, sugar, and raisins.
Simmer approx 90 minutes, stirring to avoid scorching.
Add walnuts and cook another 45 minutes or so until “thick” (i.e. 222-225 degrees).
Pour into sterile jars and process 10 minutes in boiling water bath.
For a custom touch, try adding a bit of cinnamon, nutmeg, or cardamon.