Bia hơi with a fresh raw egg yolk dropped in is a Hanoi tradition called 'bia trứng'. Stir vigorously — it's creamy and surprisingly good.
Order it at a bia hơi corner if you see locals doing it. Not for everyone, but a memorable cultural taste.
Alternative: try 'bia hoa quả' (fruit beer) for a sweeter, lighter take if raw egg isn't your style.