For the skewered prawns, soak 24 bamboo skewers in cold water for 30 minutes. Meanwhile, combine olive oil, 2 tbs of lemon juice, mustard, salt & pepper in a bowl, whisk to combine. Add the prawns and stir to coat. Cover and refrigerate for 10 minutes. Drain prawns from the marinade and thread the prawns onto the skewers.
Preheat a barbecue plate on medium-high heat. Barbecue prawns for 5 minutes, turning often until they change colour and are just cooked through.
Arrange spinach, kumato tomatoes, avocado and pine nuts on serving plates. Top with prawn skewers. Combine the oil and vinegar in a screw top jar, shake to combine. Add the yoghurt, season with salt & pepper and shake to combine. Drizzle over the salad and serve with the crusty bread.