Blend the milk with the protein powder, pour it over the chia seeds, and leave it to set in the fridge. Two to three hours is enough; overnight is better. Before serving, loosen with a splash more liquid if it has gone too firm, and add berries or coconut if you like.
The chia turns into soft pearls in a light cream. The protein thickens without sweetening. Berries or coconut add crunch and a little sharpness.