Sieve the maize flour and plain flour together in a deep bowl.
Add the oil, carom seeds and salt and knead into a semi-stiff dough using enough warm water.
Divide the dough equal portions
Roll out a portion into a circle using little plain flour for rolling and prick it with a fork
Heat the oil in a deep non-stick kadhai and deep-fry it till it turns light brown in colour from both the sides.
Once it turns light brown, immediately shape it into a shell
using a pair of tongs and a frying laddle and continue deep-frying while holding the shell till it turns golden brown in colour from both the sides. Drain it on an absorbent paper
Allow it to cool completely, store in an air-tight container and use as required.
Heat the oil in a broad non-stick pan, add the potatoes, mix gently and cook on a medium flame for 5 minutes or till the potatoes are brown from all the sides, while stirring occasionally
Combine the potatoes, onions, coriander, chaat masala, dried mango powder, chilli powder and salt in a deep bowl and toss well. Keep aside.
Fill a taco shell with 1 tbsp of the iceberg lettuce and 1 tbsp of the aloo stuffing evenly over it.
Put 2 tsp of curds, 1 tsp of sweet chutney, 1/2 tsp of coriander and 1/4 tsp cumin seeds powder evenly over it.