Slice tomatoes about 1/4" thick, but NOT ALL THE WAY THROUGH, leave a tiny bit unsliced. You want the tomatoes to open up like a fan and intack as one tomato.
Slice the bufalo mozzarella in the same width as what you sliced the tomatoes . . . about 1/4" thick
Notes
On a serving platter
Place slices of bufalo mozzarela in between each tomato slice.
Place one large basil leaf next to each slice of mozzarella cheese.