Nadiya Hussain proves that cooking frugally does not mean scrimping on flavour. She begins by transforming leftover vegetables into pakoras, with a hint of turmeric and coated in chickpea batter, then serves up a biryani with basmati rice infused with heady whole spices and a masala, all topped with more crispy fried leeks. She uses more leftovers to turn mashed potato into a burger, spiced with cumin and topped with spring onions and red chillies, and finishes off with a twist on classic shortbread, infused with cinnamon