Pour 2 1/2 cups non-dairy milk into a large jar. Add 2/3 cup chia seeds and 2 tablespoons sugar-free sweetener of choice.
Secure the lid and shake the jar vigorously for about 2 minutes (or stir vigorously) so the chia seeds are evenly dispersed and the sweetener begins to dissolve.
Refrigerate the jar for at least 4 hours, preferably overnight. If possible, shake or stir the jar once every 1 to 2 hours during the first few hours to prevent the chia seeds from settling and clumping.
When the pudding is set, open the jar and stir well to ensure an even, smooth texture.
Top with fresh blueberries, cacao nibs, and hemp hearts, then serve.