Method: To cook the potatoes: ā Place the potatoes in a saucepan with enough boiling water to just cover them and simmer for about 10-15 minutes until tender. When the potatoes are cooked, drain them in a colander and then cut them into 2cm cubes. ā Transfer them to a serving bowl and keep them warm.
To make the dressing: ā Combine the oil, mustard, garlic, lemon juice, zest and chives. Taste and season. ā Stir about 2/3 of the dressing through the potatoes along with the scallions. Reserve the rest of the dressing to drizzle over the cooked mackerel. ā Preheat the grill to high.
To cook the mackerel: ā Line a grill pan or baking tray with lightly oiled tin foil then lay the fish skin side down. ā Spread the mustard over the mackerel. Season with salt and pepper. ā Place under a hot grill and cook for approximately 6 minutes.
To serve: ā Serve the mackerel with the warm potato salad, summer vegetables and lemon wedges. Drizzle over the remaining dressing.