Preheat the oven to 350 degrees. Preheat the grill. Season the green onions with olive oil, salt and pepper. Place the onions on the grill and cook for 1 minute on each side. Remove from the grill. Drizzle each pastry shell with olive oil. Season each shell with salt and pepper. Starting in the center of the pastry, layer the potatoes, forming a swirl, on each tart. Season the potatoes with salt and pepper Lay a piece of cheese on top of the potato layer. Lay two grilled green onions on each tart. Sprinkle each tart with the bacon. Place the tarts on a baking sheet and bake for 8-10 minutes, or until the cheese melts and the tarts are golden brown. Place a tart on a plate and garnish with parsley.