Remove shells and deveign the prawns. If you are not cooking them right away, keep them in a bowl of ice water
Heat 2 tablespoons of olive oil in a non-toxic frying pan on low-medium heat. Once the pan is heated, add in the prawns and season them with the chili powder and juice from 1/2 a lime
After approximately 3 minutes, turn the prawns over to cook the other side. You will know they are cooked when they turn pink
Serve them on the salad
To a blender or food processor, add in all the dressing ingredients. Be sure to remove the white bulbs from the green onion first. Blend on high until smooth and creamy.
Toss halved tomatoes with olive oil, balsamic vinegar, salt and pepper and add them to the salad
Slice avocado and lemon wedges. Serve them on the salad with prawns and drizzle the creamy herb dressing over everything