Potato, Courgette and King Prawn Spiedini with Mustard-Smoked Paprika Mayo

• 400 g (14 oz) small new potatoes
• 2 teaspoons Dijon mustard

Soak 4 bamboo skewers in cold water for up to 1 hour (this helps prevent them burning on the grill). Meanwhile, cook the potatoes in their skins in boiling salted water until just tender (they should still be slightly firm). Drain and leave to cool, then cut in half.

In a bowl, whisk together the mustard, balsamic vinegar, oil, basil and lemon juice. Drain the bamboo skewers and alterna