Inverted Cashel Blue Burger with Roasted Tomatoes and Red Onion Salad - Cashel Blue

Ingredients

• 50g (2oz) Cashel Blue cheese
• 50g (2oz) unsalted butter
• 1 tbsp snipped fresh chives
• 675g (1 1/2oz) minced beef
• 12 baby tomatoes on the vine
• 3 tbsp light olive oil
• juice of 1/2 lemon
• 2 tsp sweet chilli sauce
• handful fresh flat-leaf parsley leaves
• 1 small red onion, cut into wafer-thin slices
• 2 muffins, halved
• salt and freshly ground black pepper