Hull the strawberries and cut larger berries into pieces.
Put the strawberries, jam sugar, balsamic vinegar, honey and rosemary sprig into a large saucepan.
Bring to the boil, stirring gently until the sugar has dissolved.
Boil for 5–8 minutes, stirring occasionally and skimming off any foam if necessary.
Remove the rosemary sprig.
Stir in the coarsely ground black pepper towards the end of the cooking time.
Pour immediately into clean, hot sterilised jars and seal.
Notes
The rosemary should complement the strawberries rather than dominate them, so use a small sprig and remove it before filling the jars.Use black pepper here rather than white pepper. Its warm, aromatic flavour is part of the recipe and works particularly well with strawberries and balsamic vinegar.For longer storage, follow safe home-preserving practices appropriate to the jars and method you use.