Devein the shrimp and cut lengthwise in half, keeping the tail attached.
Heat a ceramic plate on highest setting for 4 minutes.
Add the oil, scallions, garlic, tarragon, and white vermouth and cook for 1 minute.
Add the shrimp and continue cooking for 3 minutes.
Turn the shrimp once and rotate the dish one-quarter of a turn to ensure that all the shrimp are cooked evenly.
Serve hot, seasoned with salt and pepper.