This potato and methi tikki is filled with cheese. The cheese just melts once the tikkis are fried with the result that the tikkis taste best when they are hot.
Be careful while filling the tikkis with cheese and make sure that the cheese is completely enclosed in the potato portion. Otherwise, the cheese will ooze out of the tikki while it is being fried.
You can enjoy these tikkis with ketchup and can even make a burger out of it.
I love them with hot chole! 
Cooking Time :  10 mins.
 Preparation Time :  5 mins.
  Makes 10 tikkis.
Ingredients
 Main Recipe

1 cup grated boiled potatoes

1 cup chopped fenugreek (methi) leaves

4  green chillies, finely chopped

10 cubes mozzarella cheese [cut into 25 mm. (1″) cubes]

salt to taste
oil for shallow frying
Main Procedure
1.Combine the potatoes, fenugreek leaves, green chillies and salt in a bowl. Mix well.  2.Divide into 10 equal portions and shape each portion into a 50 mm. (2″) diameter circle.  3.Place one cube of the cheese in the centre of each circle. Bring the sides together in the centre so as to seal the cheese stuffing inside the potato circle.   4.Roll the tikki between the palms of your hands in such a way that there are no cracks on the surface. Press firmly on top to make flat tikkis.  5.Repeat the procedure and make 9 more tikkis.   6.Shallow fry on both sides in hot oil on a griddle (tava) until golden brown in colour.  7.Handy Tip(s) 1.
Two medium sized potatoes will give you 1 cup grated potatoes.   2. 
Instead of mozzarella, you can use your favourite cooking cheese.
Recipe Source 
Chaat by Tarla Dalal