There are a great many shrimp and prawns in the world's waters, and with modern fishing techniques many are raised where they happen to grow well and shipped to markets, often at vast distances. Therefore, you may or may not find gamberoni of the kind pictured here, which are 7-8 inches, or 16-20 cm long.
Found gamberoni, or something similar? You might want to try this very easy recipe from Lecce, in Puglia:
Gallipoli-Style Jumbo Prawns, or Gamberoni alla Gallipolina
To serve 4:
4 1/2 pounds (2 k) Gamberoni
1 pint (500 ml) good extravirgin olive oil (you'll likely not need all)
6 2/3 pounds (3 k) kosher salt
Salt, pepper, and whatever herbs you might like, at table
Preheat your oven to 400 F (200 C).
Line the bottom of a fairly deep, broad pot with a third of the salt. Wash the prawns well, pat them dry, and lay them out on the salt layer. Cover them with the remaining salt, and roast them for 15-20 minutes.
While they're roasting, give your diners 4 small bowls filled part way with oil, and have them season their oil as they prefer. Bring the roasted prawns to the table still encased in salt; break open the crust, remove the first round of shellfish, and enjoy, dipping the prawns into the seasoned oil; your diners can eat at their own pace, while the salt in the roasting pan will keep the prawns hot.
Gamberoni on About:
Chinese Prawns With Hot Bean Sauce
Indian Prawns Rava Fry (semolina batter-fried prawns)
Greek Garithes me Ouzo: Flambéd Prawns with Ouzo
How to Select Fresh Fish