• Preheat the oven to 350 F (180C Fan oven).

To start, prepare the samosa covering, by making a very easy pastry:

• In a large bowl, mix together the all-purpose flour, ajwain, salt and bicarbonate of soda.
• Add the oil to the bowl and mix well, ensuring the oil is spread throughout the dry ingredients.
• Start adding water and mix well, using your hands. Add enough water to form a soft dough which is easy to roll, but not so soft that it is sticky.
• Knit the samosa wrapper in a ball and keep it in the bowl; cover the bowl with some cling film or a clean damp tea towel.

Next, prepare the spiced potato filling:

• To start, prepare the samosa masala by lightly toasting cumin seeds, coriander seeds, and fennel seeds in a sauce pan on a low heat; do not use any oil and only toast them lightly, until their aroma is released.
• Move the toasted seeds to a mortar and, using the pestle, crush them to form a coarse powder; set it aside.
• Warm up some oil in the sauce pan and, once warm, add the samosa masala to it; allow the masala to gently fry on a low-medium heat.
• Once the masala releases its aroma and it turns lightly brown, add the freshly chopped ginger and green chillies. Mix these well and allow them to fry until the smell of rawness has gone.
• Next, add the red chilli powder, hing, turmeric powder, coriander powder and chaat masala to the pan and mix well; allow the spices to cook, which should take around one minute.
• Add the boiled potatoes to the masala; ensure the potatoes are peeled and diced and they must not be overboiled. It is better to use cold potatoes at this stage, as they do not release much water.
• Mix well the potatoes with the masala, then top the spiced potatoes filling with the lime juice and coriander.
• Mix well and set aside to cool down.

Now the final step is to prepare the samosa covering in the right shape to wrap the filling:

• Divide the samosa pastry dough in 5 balls of equal size.
• Roll one ball into a circle (like a chapatti) that is about 1/10inch thick (2mm).
• Cut the circle into two semicircles; if needed, once cut in two, roll the pastry a bit further.
• The middle part of the straight side of the semicircle will form the tip of your triangle, so fold one side half way and wet the outer edge with a little water.
• To finish forming the triangle top, fold the other half until it meets the wet edge, slightly overlapping the two. Pinch the two edges together, so they do not separate.
• Hold the pastry in your hand like a cone and fill it with some spiced potatoes.
• Pull the round part of the pastry across the bottom of the samosa and pinch together with the other edges.
• You now have a triangular samosa which should be standing on a flatter bottom.
• Do so until you have 10 samosas, then place them all on a baking tray that has been covered with a sheet of parchment paper.
• Bake the samosas for 18-20 minutes in the middle of the oven, which has been preheated to 350 F (180C Fan oven).
• Enjoy!