1) Preheat a sandwich toaster or a panini press to a medium-low heat.
2) Arrange the slices of mozzarella over 1 slice of the bread. Sprinkle with salt and pepper. Add the slices of tomato and sprinkle with the basil leaves.
3) Top the sandwich with the second slice of bread slice. Brush both sides of the sandwich with the oil.
4) Toast the sandwich until the bread is golden brown and the cheese has begun to melt, about 2 to 4 minutes.