Final answer:
The architectural firm established in Hong Kong and recognized in the Philippines, especially for projects like the Philippine Plaza and Pacific Plaza Towers, and awarded 'firm of the year' by the Philippine Institute of Architects in 1997 is Recio + Casas.
Step-by-step explanation:
The architectural firm established in Hong Kong in October 1988 by young architects, known for notable projects such as the Philippine Plaza, ABS-CBN Complex, Kingswood Gardens, One and Two Lafayette Square, Salcedo Park, and the Pacific Plaza Towers, and awarded the prestigious title of 'firm of the year' in 1997 by the Philippine Institute of Architects, is Recio + Casas.