One-pot paneer curry pie - Good Food Middle East

Ingredients

• 2 tbsp vegetable oil
• 440g paneer, cut into 2cm cubes
• 4 tbsp ghee or butter
• 2 large onions, finely sliced
• 2 large garlic cloves, crushed
• thumb-sized piece of ginger, finely grated
• ½ tsp hot chilli powder
• 2 tsp ground cumin
• 2 tsp fenugreek seeds
• 1½ tbsp garam masala
• 2 x 400g cans chopped tomatoes
• 1 tbsp caster sugar
• 300g potato, peeled and cut into 2cm cubes
• 150g spinach
• 150g frozen peas
• 100ml double cream
• 2 tbsp cashew nut butter
• plain flour, for dusting
• 320g sheet all-butter puff pastry
• 2 large eggs, 1 whole, 1 yolk only, lightly beaten together (freeze the leftover egg white for another recipe)
• 2 tsp nigella seeds
• pilau rice or green veg, to serve