Place the berries in a medium pot and heat on medium high. You don't need to add water, as the berries will quickly start to release their own juices.
When the berries have softened, crush them with a potato masher until there are no whole berries left. If you like a chunkier jam, stop there. If you like a smoother jam, continue to mash the berries until they reach desired consistency.
Continue to cook over medium to medium high heat, until most of the liquid has boiled off and the mixture has a thick consistency.
Take off the heat and add the chia seeds. Stir to combine. The chia seeds will begin to absorb the liquid and grow slightly in size. They will take on a jelly-like consistency and help to thicken up the jam. Wait at least 15 minutes before consuming.
Store in the refrigerator in a glass, air tight container for up to 7 days.