Heat oil in a pan on medium flame, add mustard seeds, cumin seeds, green chilli, asafoetida and green peas, cook for 2-3 min until peas are tender.
Add Coriander powder, chilli powder, potatoes and mix well.
Now add salt, dry mango powder and lemon juice, stir-fry for about 3-4 min. Keep aside to cool to room temparature.
In small bowl take 1 tsp of all-purpose flour and little water and make a paste and keep aside.
Now cut one samosa sheet into halves.
Fold each half to form a cone shape. Fill the cone with the potato mixture and seal the cone with maida paste.
Repeat procedure with other halves of the samosa sheets.
Preheat the oven to 200 C. Spray or brush the samosa with oil or milk.
Sprinkle some flour on a baking tray and arrange the samosa in it.
Now bake the preheated oven at 200 C for 10 minutes and then brush it with oil again and then bake it on the other side for 10 more minutes till golden brown and crisp.
Serve hot with tomato ketch-up or mint chutney and enjoy.