To make dressing; whisk achiote paste, garlic, juice, vinegar, oil, cumin and cinnamon in a bowl until achiote paste has dissolved. Season.
Put beans in a heatproof bowl and cover with boiling water. Stand for 3 minutes. Drain and refresh with cold water. Drain. Put beans, tomatoes, onion and coriander in a bowl and stir until combined.
Heat oil in a large non-stick frying pan and put over a high heat. Cook fish, skin side down for about 5 minutes or until crisp and golden. Turn fish over and cook the other side for 4-5 minutes or until cooked through.
Spoon bean mixture onto plates or into flat bowls and top with fish. Spoon over achiote dressing and serve