Mozzarella Basil Melt

6 slices sourdough sandwich bread
1 tablespoon olive oil
15 fresh basil leaves
2 firm-ripe tomatoes, sliced 1/4-inch thick
4 ounces fresh mozzarella cheese, sliced 1/4-inch thick
Salt and pepper, to taste

Brush one side of each bread slice with olive oil. Place three slices, oil side down, on a 10 x 15-inch baking sheet and layer evenly with basil leaves, tomato slices and mozzarella slices. Sprinkle with salt and pepper. Top with remaining bread slices, oil side up. Broil sandwiches 6 inches from heat, turning once, until bread is golden brown and cheese is melted, 2 to 3 minutes total. Serve immediately.