Add everything to a jar: Add the oats, protein powder, Greek yogurt, cocoa powder, water and chia seeds to a jar or glass. If you're using frozen berries, add them now too.
½ cup rolled oats, 2 tablespoon whey protein isolate powder — vanilla or unflavored, ⅓ cup plain Greek yogurt, 1 tablespoon unsweetened cocoa powder, 3½ tablespoon water, 1 tablespoon chia seeds, ⅓ cup mixed berries — raspberries, blueberries, blackberries
Mix well: Stir everything together until the cocoa powder is fully combined with no dry patches. The mixture will look quite thick — that's correct.
Refrigerate overnight: Seal the jar and place it in the fridge for at least 6 hours, or overnight. The oats and chia seeds will absorb the liquid and thicken up.
Serve: In the morning, give it a stir. Top with fresh berries and eat straight from the jar.
Notes
Use rolled oats, not instant — instant oats go mushy overnight
Whey protein isolate mixes more smoothly than concentrate
Keeps in the fridge up to 4 days — add fresh berries on the day