Reserve 20 small pieces of watermelon for garnish. Working in batches, place the remaining watermelon, the cucumbers, red bell peppers, onion, jalapeno pepper, lemon juice, olive oil, 3 tablespoons of fresh mint, the ginger, honey, and pineapple juice into a blender, and blend for about 30 seconds per batch. The mixture should be well blended but retain some texture. Pour into a large pitcher or bowl, and refrigerate 1 hour. Serve in bowls, and garnish each bowl with a couple of chunks of the retained watermelon and 2 small mint leaves.