Preheat barbeque to medium heat (350F) (176C)
To help prevent the fennel and pear from sticking to the grill grates rub or spray the grill with oil and drizzle the ingredients with olive oil. Season the fennel to taste with salt and pepper.
Start cooking the fennel first and cook on one side for 4-5 minutes or until golden char marks are achieved.
Flip the fennel and continue to cook for another 4-5 minutes. Add the pears to the grill and cook them for 2 minutes per side or until nice golden char marks appear and pears are slightly softened.
Remove all of the veggies and fruit from grill, drizzle with sherry vinaigrette and toss with the watercress. Add more of the vinaigrette to taste as desired.
Prepare the dressing by placing all of the ingredients into a small jar, cover with a lid and shake vigorously until well combined. Season this mixture to taste with salt and pepper.