Prepare an outdoor grill with a medium-high fire. If you're using wooden skewers, soak them in water for at least 30 minutes before grilling. (Or you can use wooden toothpicks.)

For the scallops: Slice the zucchini lengthwise on a mandoline into thin slices, about 1/8- inch thick. When you get to the seedy center, rotate the zucchini 1/3 turn and continue to shave slices until you hit seeds. Give the zucchini a final 1/3 turn and shave off the remaining slices. (You want to end up with the same number of zucchini slices as you have scallops.) Discard the seedy center. Wrap a zucchini ribbon around the circumference of each scallop. Thread 2 to 3 scallops per skewer or 1 per toothpick.

For the dressing: Whisk the mint, chives, orange juice, 2 tablespoons oil, lemoncello, salt, and cayenne in a small bowl. Set aside.

Cut up the tomatoes, season them with salt and black pepper to taste, and divide them among 4 plates.

Brush scallops with oil and season with salt and black pepper to taste. Grill, turning to cook both sides, until zucchini and scallops are cooked through and have distinct grill marks, about 8 minutes total. Divide the scallops evenly among the plates, drizzle scallops and tomatoes with the dressing, and serve hot or at room temperature.