www.youtube.com/embed/rTtlAiAEPVI Yeouido's Best Kept Secret: Unveiling Gayang Kalguksu 버섯매운탕 (Mushroom Hot Pot) Yeouido, Seoul's bustling financial district, is not just about towering skyscrapers and busy professionals. Hidden beneath the surface, especially in the basements of office buildings, lies a treasure trove of 맛집 (matjib - delicious restaurants) beloved by locals. In a recent episode of the popular Korean food vlog "TtoganJip," hosted by the charismatic…