Okay, so this recipe isn't devoid of all sugars. Just refined sugar. I used honey, instead. Which is expensive. But if you are trying to avoid refined sugar---then maybe it is worth a try. And if your father-in-law knows a professional beekeeper? Well, you might also be in luck! And since this recipe has no expensive store-bought pectin---well, the cost comes out about even!
In a large pot, cut up two large baskets of strawberries and one shredded apple--with the peel left on.
Add 1 1/2 cups of honey and the juice of one lemon.
Boil and stir.
This jam is very tart and has a lovely texture. What I like best is that it required NO PECTIN. Apples have lots of natural pectin and so allow the jam to set. Also I love that there is no refined sugar.