In a bowl, mix the oil, garlic, coriander, cumin and pepper. Add the fish cubes and let it stand for 30 minutes (a few hours would be perfect, as it would allow the spices to seep into the fish)

Thread the marinated fish pieces in the skewers and place on an oiled oven tray. Cook under the oven grill, turning frequently, for about 7 minutes (depends on size of fish cubes)

Serve warm with cool bubbling mineral water