Grilled Chicken with Charred Lemon and Heirloom Tomatoes

INGREDIENTS

• 2 bunches scallions, roots trimmed
• 1 lemon, sliced
• 1 tablespoon red wine vinegar
• 1/2 cup chopped fresh parsley
• 1 to 2 pinches crushed red pepper flakes
• 6 to 8 medium very ripe heirloom tomatoes or juicy beefsteak tomatoes, cut into wedges
• 1 tablespoon Worcestershire sauce
• Salt and freshly ground black pepper
• 2 to 3 anchovies, well rinsed, finely chopped, optional
• 2 whole chickens, 2 1/2 to 3 pounds each, cut into 8 pieces
• 2 medium onions, sliced into 1/2-inch-thick rounds
• 4 to 6 slices ciabatta bread
• 1 1/4 cups extra-virgin olive oil, plus more for brushing