Preheat the oven to 180°C / 160°C fan / 350°F / gas 4. With a knife, prick the sweet potato and bake them in the oven for about half an hour or until they are soft. While your sweet potatoes are cooking boil the peas.
Take the sweet potatoes out of the oven and let them cool until you can handle them. Then scrape the sweet potato into a bowl.
Add all the other ingredients to your bowl with the sweet potato, apart from the mustard seeds and cheese.
Using a fork mix all the ingredients together until it resembles mashed potato.
In a medium heat saucepan cook the mustard seed until they start to pop. This should take between 30 seconds and a minute. Add them to the mixture and give a good stir.
Cube up the cheese and sprinkle into the mixture and gently mix through. Turn the oven up to 200°C / 180°C fan / 400°F / gas 6.
Make the samosas using the step by step photo guide above. Bake them for 20 minutes or until golden and crispy.
Once your samosas are out of the oven serve straight away so they don't loose their crisp. Serve with a large helping of yogurt dip and a handful of coriander. Enjoy!