Have you heard of chia seeds? I reviewed them before. They have an insane amount of fiber, and make their presence known by texture more than taste. Dry chia seeds are crunchy. When soaked, the seeds absorb the liquid and develop mucilage - which just means they get a little polysaccharide gelatinous coating.
This property is vital in order for chia seed puddings to work. In all the variations I've found, chia seeds are mixed with a non-dairy milk (probably to retain the vegan aspect), and let sit, with occasional stirring. After a couple hours (or overnight), the mixture has thickened substantially, forming a "pudding." Fruit, purees, nuts, and flavorings are added afterwards.
