Puree the pineapple strawberries, freed from the stalk and cleaned, with the preserving sugar. Let it simmer for 4 minutes in the saucepan without a lid, stirring constantly. Then immediately fill into twist-off glasses rinsed with hot water and close tightly.
The jam does not become completely transparent, as is often assumed, but keeps its slightly pink color. The red nuts of the strawberries stand out as a funny eye-catcher. A very fruity, delicious jam.