Grill steaks 10 to 14 minutes for rare (140 °F) to medium (160 °F)., turning once.
Season with salt and pepper, if desired.
Meanwhile cut bread in half lengthwise, and brush with 1 ½ tablespoons of the basil mixture, evenly on cut side of bread.
Brush remaining basil mixture on one side of each tomato slice.
About five minutes before steaks are done, place bread, cut side down and tomatoes, on grid with steaks; grill 2 to 3 minutes or until bread is golden brown and tomatoes are just heated through.
Cut bread diagonally into slices, so some of the seasoning is on each slice.