Peel the potatoes or leave the skin on. Add the whole potatoes to a saucepan of boiling water and cooked for 15 minutes, until tender. Remove with a slotted spoon and drain. Add the peas to the boiling water and cook for 3 minutes, then drain and rinse under cold running water.
Slice the potatoes and place in a serving bowl. Drain the oil from the tuna into a bowl, then flake the tuna over the potatoes. Add the carrots and peas.
Add the lemon juice to the tuna oil. Season with salt and freshly ground black pepper, then add enough mayonnaise to make 350 ml (12 fl oz). Whisk until combined, then stir the dressing through the salad.
Arrange the eggs on top of the salad and sprinkle with the chives or parsley. Cover and chill for 30 minutes before serving.
Tip: Chives are best chopped with a pair of scissors to avoid squashing and bruising the tender stalks.
Per serving: 783 calories, 36 g protein, 55 g fat (8 g saturated fat), 36 g carbohydrate (15 g sugars), 6 g fibre, 1304 mg sodium