Cut meat across the grain into thin strips. In a bowl, mix beef with fish sauce. Cover and let marinate while preparing remaining ingredients. In a colander, rinse bamboo shoots with cold water, drain and cut into strips. Rinse basil, shake dry, strip leaves from stems and cut leaves into thin strips.
Scoop out solidified or thickened parts of coconut from the can into a saucepan. Bring to a boil. Stir in curry paste and cook, stirring, 2-3 minutes. Add beef and sauté about 2 minutes. Add remaining coconut milk and season with salt and sugar. Add bamboo shoots and simmer about 5 minutes over medium heat. Stir in basil and mint to taste, and infuse about 2 minutes.
Divide beef curry among plates and serve garnished with orchid flowers.