Put the strawberries and 10 ml of the peppercorns into a large heavy-based pan.
Bring to a boil, then reduce the heat and simmer until soft.
Crush well to release their juices.
Ladle the fruit and juices into a scalded jelly bag.
Strain the juice through the jelly bag overnight into a bowl.
Do not squeeze the bag or the jelly will be cloudy.
Measure the juice into a large heavy-based pan and to every 600 ml of juice allow 400 g of sugar and 45 ml of lemon juice.
Heat the juice, sugar and lemon juice in the pan and stir over a low heat until the sugar has dissolved completely.
Add the remaining peppercorns, bring to a boil and boil rapidly until setting point is reached.
Skim off any scum and pour into hot sterilised jars.
Cover, seal and label.