In a glass jar with a lid (or a cocktail shaker), combine the mint leaves, strawberry jam, gin and Campari. Squeeze the juice from the lime into the jar and toss the rind into the jar. Add a handful of ice. Cover and shake vigorously for 30 seconds.
Add ice to a rocks glass. Strain the cocktail into the glass. Top with lime soda water and garnish with a strawberry and piece of mint.
