Clean the prawns as mentioned and keep aside.
Make the herb marinade by mixing all the fresh herbs with the olive oil.
Marinate the prawns with ¾ ths of the herb marinade (reserve a bit for the end), half of the chilli flakes, salt, garlic and the lemon juice.
Heat a stove top grill to high, season with oil and grill the prawns on both sides till done.
Remove to a serving plate, mix through the remaining marinade and garnish with chilli flakes and lemon slices.
Enjoy!