Put the chopped sweet potatoes into a pot, pour water over them and let them cook until they are just tender about 10 to 15 minutes.
Meanwhile, brush the sea bream fillets with oil and season with salt.
Simply place the fillets, skin side up, under a medium-hot grill until lightly charred and the flesh is easily pierced with a knife.
Drain the sweet potato, place it on a heatproof bowl and stir in the yoghurt, mustard, onion and coriander until well combined.
Serving Suggestions: Put a scoop of potato salad on each plate, top with toasted pumpkin seeds, season and enjoy with the grilled fish.