Smoked mackerel, orange and beetroot salad recipe

Ingredients

• 1 squeeze of lemon juice
• 300 g waxy potatoes, unpeeled, cut lengthways into 5mm (0.25 inch slices)
• 4 smoked mackerel fillets
• 2 oranges
• 4 tbsp light olive oil
• 2 tsp wholegrain mustard
• 80 g watercress
• 8 basil leaves
• 1 pinch sea salt and freshly ground black pepper
• 2 large raw beetroots, unpeeled, washed and leaves trimmed to 3cm (1 inch)