• Preheat your oven to 220°C/200°C fan/gas mark 7.
• Chop the potatoes into 2cm chunks. 
• Pop the potatoes onto a large (lined) baking tray.
• Toss with salt, pepper and a drizzle of oil.
• Spread out in a single layer (leaving room for the meatballs) then set the tray aside.

• Add the beef mince, breadcrumbs, half the mustard (double for 4p) and Worcester sauce to a large bowl.
• Season with salt and pepper then mix everything together by hand.
• Once combined, form into evenly-sized meatballs, 3-4 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.

• Meanwhile, place a pan over medium-high heat with a drizzle of oil.
• Add the chopped tomatoes, 1 tsp sugar and 50ml water (double both for 4p).
• Simmer until slightly thickened, 5-7 mins.
• Stir in the spinach and cook until wilted and warmed through, 1-2 mins.
• Season to taste with salt and pepper. Stir through a knob of butter.

• 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 simmered spinach sauce. 
• Drain then roughly tear the mozzarella.
• Scatter the mozzarella evenly over the top.

• Place the oven dish below the potatoes in the oven.
• Bake everything until the mozzarella has melted and the potatoes are golden, 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.