Ingredients

• 125g/4½oz mozzarella ball, drained and torn into walnut-sized pieces
• 4 tbsp extra virgin olive oil, plus extra for drizzling
• ½ tsp dried oregano
• 1 garlic clove, finely sliced
• 1 unwaxed lemon, juice and pared zest
• 1 courgette, sliced into 5mm/¼in rounds
• 1 red onion, sliced into 5mm/¼in rounds
• 1 small focaccia (about 20cm/8in square)
• 2 tbsp mayonnaise
• 1 tomato, sliced into 1cm/½in rounds
• salt and freshly ground black pepper

Instructions

1. In a wide jar or small bowl, combine the mozzarella with the oil, oregano, garlic and lemon juice and zest and press down with a spatula to submerge under the oil. Sprinkle over some salt and pepper then press down again. Set aside.

2. Preheat the grill to high.

3. Toss the courgette and onion together on a baking tray and drizzle with 2 tsp olive oil. Season lightly with salt, then turn to coat in the oil.

4. Grill for 5–7 minutes until the vegetables are browning in places, turning once. Warm the focaccia under the grill for the final 2 minutes.

5. Slice the focaccia in half horizontally. Place the bottom half cut-side up on a chopping board. Spread the mayonnaise over the focaccia base and top with slices of tomato.

6. Lift the mozzarella out of the oil and arrange over the tomatoes (you may not need it all). Spoon the grilled vegetables on top, drizzle a little of the mozzarella marinating oil over everything.

7. Add the top piece of focaccia and slice in half to make two sandwiches. Wrap up tightly in parchment paper if you're taking it out on the go.