Prepare a medium fire in your grill.
Combine the pine nuts, garlic, basil, and mustard in a blender or food processor and puree.
With the motor still running, add the oil in a steady stream. Turn off the motor, add the vinegar
and lemon juice and pulse to blend. Season with salt and pepper. Set aside.
Thread the mozzarella and bread cubes alternately onto skewers and sprinkle them with salt and pepper. Grill over a medium fire until the bread is nicely browned and the cheese begins to melt, 2 - 3 minutes per side.
In a large bowl, combine the arugula, Radicchio, tomatoes, and olive, if you want them. Stir the dressing well, add just enough to moisten the ingredients (you may have some left over), and toss to coat. Slide the mozzarella and bread cubes off the skewers onto the top of the salad and serve.