Preheat a griddle pan or barbecue (grill side, not hotplate side) on high.

Place bread on the barbecue or griddle pan, and cook each side until nicely toasted and golden brown with char lines. You can also toast the bread in a toaster or grill/broil.

Remove from heat and rub the surface of the bread lightly with the garlic.

Cut 5 1/2 of the celery sticks into chunks (about 4 cups) and place into food processor with remaining ingredients and whizz until smooth. Season to taste with salt and pepper.

Dice the remaining 1/2 celery stick. Stir into the celery puree.

Spread topping onto bread. Drizzle with extra virgin olive oil and serve immediately.