Preheat the oven to 180°C and line a baking tray with non-stick baking parchment. Place the eggs in a pan of boiling water and simmer for 6 minutes. When they are cooked, drain and place in a bowl of iced water. Leave to cool.
In a bowl, add the beef mince, red onion, garlic powder, garam masala, chilli powder, coriander and turmeric. Season with a little salt and pepper. Mix well, and then roughly mark into four sections within the bowl. Leave to one side.
Spray a saucepan with low-calorie cooking spray and add the red onion. Fry for 3 minutes. Add the garlic and ginger and continue to fry for a further 2 minutes. Add the garam masala, turmeric and chilli powder and fry for 1 minute; allow the flavours of the spices to become fragrant.
Crumble in the stock cube and add the tomato puree, boiling water, and butternut squash stir and bring to the boil. Lower the heat and simmer for 15-20 minutes, until the butternut squash is soft.
Peel the eggs carefully. Take a fourth of the beef mixture and press flat in the palm of your hand. Place an egg in the centre and enclose the egg in the beef mixture. Press and roll tightly round the egg and roll into a smooth ball. Place onto the baking tray and repeat with the remaining eggs.
Spray with low-calorie cooking spray and pop into the oven for 20 minutes. Turn them halfway to get an even colour all round.
Once the butternut squash is cooked, remove the pan from the heat. Blitz with a stick blender until smooth – we left ours with a little bit of texture, but it's up to you how smooth you'd like the sauce. Stir through the Greek yoghurt and chopped coriander.
Remove the eggs from the oven. Add the sauce to your serving plates and add an egg on top of the sauce. Serve with a little extra coriander (optional) and your choice of accompaniment.