Add the cherries, maple syrup and lemon juice to a pan with a splash of water. Bring to a boil while stirring and simmer for 10-15 minutes, stir occasionally. Once the cherries are nice and soft and juicy, take the pan off the heat. 

Taste it and adjust with more maple syrup if desired, the amount needed depends on how sweet your cherries are.

Mash the cherries using a fork to a chunky consistency. Stir in the chia seeds and let cool in the pan for 15 minutes. 

The jam will thicken while it cools. Store the jam in a airtight container in the fridge for about one week.