Pressure cook potato until soft(for 4 whistles), peel off the skin and slice them to 1/4 inch thickness.
Then slice onions.
Slice tomato and get ready with your veggies.
Now in a mixing bowl add the ingredients listed under ‘to marinade’.
Mix well and set aside to marinate.
Meanwhile prepare the white sauce.
Heat butter once it starts to melt add maida and give a quick mix until it resembles sandy texture.
Then add milk and keep cooking till it starts to thicken.
Now add oregano and keep cooking until the sauce coats the back of a laddle,creamy and thick.Set aside to cool down.
Now take your potato slices, dip it in the spice powder marinade and toast it in a dosa tawa till golden brown on both sides.
Next coat onion slices with the spices mixture.
And toast it till slightly browned.
You can add raw tomato itself to your sandwich but I wiped off the remaining spice mixture and toasted it.
Now the toasted veggies are also ready.
Now spoon a generous mixture of prepared white sauce and spread it in 4 slices of bread.
On one side of the bread add the toasted potato,onion and tomato slices.
Close the sandwich with the other bread, press it slightly so that it gets sealed.
Heat dosa tawa drizzle ghee and add one sandwich at a time and toast it till golden brown.
Flip to other side and cook.
While toasting just press the bread with a flat laddle to get the toast evenly browned as shown below.
Cut into half and Serve hot ….yummm!! Enjoy the spicy , creamy Potato sandwich!!