Tie the sprigs of fresh herbs together with butchers twine to form a small brush. Dip the end of the brush into the cup of olive oil and allow to soak while preparing the other items.
Prepare the lobster tails by cutting them in half lengthwise and removing any veins, then season lightly with salt and pepper
Preheat the grill to high, then use the herb brush to brush an area of the grill bars and place a lobster tail, meat side down, in that spot (this will keep the lobster from sticking to the grill).
Return the brush to the oil and brush another spot on the grill, until each of the tails has been placed face down.
Each time the herbs brush the grill they will get a slightly more intense grilled flavor. Keep placing the herbs back into the bowl of olive oil between each brushing, which will intensify the flavor of the oil.
Grill the tails on the first side for 1-2 minutes, then turn them over and cook until they simmer inside their shells.
Grill the scallions in the same manner, using the herb brush, just until they wilt and lightly darken on each side. Season them lightly with salt and pepper while grilling, then arrange them on a large platter.
Remove the tails from the grill when they are ready, then remove the meat from the shells (if desired).
Place the tails on top of the scallions and drizzle the platter liberally with the herb-infused oil and serve.