• Preheat your oven to 220°C/200°C fan/gas mark 7.
• Chop the potatoes into 2cm chunks (no need to peel). 
• Pop the potatoes onto a large (lined) baking tray.
• Drizzle with oil, season with salt and pepper then toss to coat.
• Spread out in a single layer (leaving room for the meatballs).

• To a large bowl, add the beef mince, breadcrumbs, mustard and Worcester sauce.
• Season with salt and pepper then mix everything together with your hands.
• Once combined, form into evenly-sized meatballs, 5 per person. IMPORTANT: Wash hands and equipment after handling raw meat.

• When the oven is hot, cook the potatoes and beef meatballs together for 15 mins.

TIP: Use two baking trays if necessary.

• When the potatoes and meatballs have been cooking for 15 mins, remove the meatballs from the oven (leaving the potatoes to cook).
• Add the meatballs to an oven dish.
• Stir in the spinach, chopped tomatoes, salt and pepper. 
• Roughly tear the mozzarella and spread it on top.

• Place the meatballs in the oven below the potatoes.
• Cook everything until the mozzarella has melted and the spinach has wilted, 10-15 mins. IMPORTANT: Mince is cooked when no longer pink in the middle.

• Divide the mozzarella meatballs between plates.
• Serve with the crispy potatoes alongside.