Wash the potatoes and cut them into 1 cm thick slices.
Place the potatoes in a pan of salted water at a rolling boil and cook for around 10 minutes until they are almost soft.
Drain the potatoes and set them aside to cool. Later, put them in a bowl and mix them together with a little olive oil.
Cut the vegetables and mushrooms into small cubes. Finely chop the garlic. Thinly slice the spring onions.
Fire up the grill. Put on the potatoes and grill until golden. Then transfer them to a baking tray and reheat in the oven or on the grill just before serving.
Put a frying pan on the grill and let it heat up. Add olive oil, mushrooms and grill for about 2 minutes.
Then add the onion and sauté for another 1 minute.
Finally, add the peppers, courgette and garlic and sauté for about 2 minutes.
Pour the lemon juice over the vegetables, let this reduce, then season with salt and pepper and remove the pan from the heat and store in a warm place. Stir in the tomato, spring onions and herbs.
Drizzle the saithe with olive oil and season with salt and pepper.
Put the saithe on the grill and cook for around 3 minutes each side.
Serve up the potatoes, vegetables and saithe. Drizzle with a little olive oil. Scatter over a little of any leftover herbs.