While grill heats, toss eggplant in olive oil and salt. Once grill is up to temperature, add eggplant directly on grates on a single layer over indirect heat (not directly over the flames). Close lid and grill for 10-12 minutes. Open lid, flip, and grill for another 2 minutes with the lid closed.
Spoon pizza sauce over each slice, evenly dividing between slices (aboutu 1-2 tablespoons on each one). Sprinkle each slice with cheese as well. Close lid of grill and grill from another 2-3 more minutes, until cheese is melted. Top with fresh basil and red pepper flakes and enjoy!