Wash, clean and cut the strawberries into pieces. Weigh 900 g cleaned fruits. Peel oranges so that the white skin is completely removed. Then cut them into thick slices. Weigh 300 g fruit flesh.
Mix 2 tablespoons of sugar, gelling agent, fruit and Campari in a large pot. Bring to the boil while stirring constantly. Add the remaining sugar, bring to the boil again briefly, then boil for 1 minute until bubbly. Skim the jam. Pour into prepared glasses and close immediately