Combine salt and 500ml water in a saucepan over medium heat, stir until dissolved, and set aside to cool. When cold, place fish in the brine, chill for 1 hour.
Add 2 cups olive oil and crushed coriander to a small saucepan, bring slowly to 60°C.
Prepare a steamer, bring to a boil, then reduce heat to low until simmering gently. Remove trout from the brine and lightly rinse, line the steamer with baking paper, steam trout for 1 minute until just warmed through.
While the trout is still warm, carefully place onto paper towel and gently pat dry. Immediately place trout into the oil and coriander confit bath for 4 minutes. Remove, set aside until just warm.
Arrange the salad leaves around each plate, add the trout and scatter with a little sea salt and artichoke pieces.
Combine broad beans, tomato, parsley, garlic oil, extra virgin olive oil, lemon juice and any juices from the trout with a pinch of sea salt. Spoon the tomato and beans over and around the salad to dress it.