Indian-Spiced Shepherd's Pie | Nigella's Recipes | Nigella Lawson

Ingredients

• 1 kilogram sweet potatoes
• 2 teaspoons Maldon sea salt flakes
• 2 x 15ml tablespoons white peppercorns
• 6 cardamom pods (cracked)
• peeled strips from 1 unwaxed lime and juice of ½ lime
• 4 centimetres piece fresh ginger (peeled) - plus more for filling (see below)
• 3 cloves garlic (peeled)
• 4 centimetres piece fresh ginger (peeled)
• 1 onion (peeled)
• seeds from 6 cardamom pods
• 2 teaspoons cumin seeds
• 2 teaspoons coriander seeds
• 2 x 15ml tablespoons cold-pressed coconut oil
• 2 teaspoons garam masala
• 1 teaspoon dried chilli flakes
• 1 teaspoon ground turmeric
• 500 grams minced lamb
• 1 x 400g can chopped tomatoes
• 100 grams red lentils
• 1 teaspoon Maldon sea salt flakes
• 2 x 15ml tablespoons Worcestershire sauce
• 4 teaspoons nibbed or finely chopped pistachios