Take a clean, sealable jar or a sturdy glass. Add the three tablespoons of chia seeds and pour in the 200ml of unsweetened almond milk. Immediately add the half teaspoon of sugar-free vanilla extract. Stir everything together vigorously with a spoon, so the chia seeds can absorb the liquid well and don't stick to the bottom.
Let the mixture sit on the counter for ten minutes. Stir it thoroughly again to remove any lumps and create a smooth mixture. Cover the jar or glass and place it in the refrigerator. Let the pudding rest quietly for at least two hours, or preferably overnight, until it sets.
Take the set pudding out of the refrigerator. Rinse the 50g of fresh blueberries under cold running water and pat them dry with a piece of paper towel. Distribute the berries evenly over the top of the pudding.
Finally, sprinkle the tablespoon of sliced almonds evenly over the fresh blueberries for a crispy texture. Serve the cold chia pudding immediately.