Open beef burgers

1.Combine mince, breadcrumbs, egg and 2 tablespoons of the pesto in a large bowl. Shape into 4 patties. Heat half the oil in a large frying pan over moderate heat. Cook patties for 3-4 minutes each side or until browned and cooked. Remove from pan; place on a baking tray.

2.Add remaining oil to pan; cook and stir onion for 2-3 minutes or until golden. Remove from heat.

3.Preheat an oven-grill to moderately high. Cook focaccia under grill until golden. Sprinkle patties with cheese. Cook patties under grill until cheese bubbles and is melted. Whisk mayonnaise and remaining pesto. Place one piece of focaccia on each serving plate. Spread each focaccia with half the pesto mayonnaise. Top with spinach, tomato, onion and patties. Top with remaining pesto mayonnaise. Serve burgers with wedges