1.To make coriander dressing, blend or process ingredients until smooth.
2.Rub half the coriander dressing over tuna; cover, refrigerate 1 hour.
3.Boil, steam or microwave potatoes until tender; drain, slice thickly.
4.Cook tuna on a heated oiled grill plate until cooked as desired.
5.Combine remaining coriander dressing with oil and lemon juice.
6.Combine potato, onion, nuts and spinach; divide among serving plates. Top with tuna and drizzle with remaining coriander mixture. coriander dressing blend or process ingredients until smooth.
You can use lime juice instead of lemon juice, if you prefer.Note