Coat the bottom of a large skillet with olive oil and heat until shimmering. Season the eggplant slices with salt and pepper and cook over moderately high heat until golden, 6 to 7 minutes per side. Top each eggplant slice with a slice of cheese and cook until the cheese begins to melt, 1 to 2 minutes. Transfer to paper towels to drain. Wipe out the skillet and add more oil. Repeat with the remaining eggplant and cheese.