Preheat the grill to medium high heat or heat a grill pan.

Arrange the chicken on a platter.

Whisk 1 tablespoon basil pesto with the olive oil and brush to coat the chicken on both sides.

Grill the chicken for 4-5 minutes and then flip. Continue to grill for an additional 5 minutes or until cooked through. Internal temperature should read 165˚F on an instant read thermometer.

Toast the bread on the grill for 1 minute on each side.

Brush the remaining pesto on one side of each slice of bread.

Build the sandwich by layering two slices of mozzarella on two separate pieces of bread.

Top the cheese with the chicken and then arrange the tomato slices on top.

Sprinkle the sprouts over the tomatoes and top with the remaining slices of bread.

Cut in half and serve immediately.