Not the classic combo... but a damn fine one I promise!
Weigh the raspberries into a saucepan and zest over the lime before squeezing in the juice. Tip in the same amount of caster sugar and the weight of berries and heat to a boil
Boil for 10 minutes and then leave to cool. If you want to check the consistency of the jam then spoon a blob onto a cold/frozen plate to speed up the cooling process and check that it sets to the consistency you want. If it's too runny... just boil for another few minutes.