Heat oil in a heavy bottom pan add oil/ghee to shallow fry tikkis. Or heat a a griddle, arrange tikkis on it, and add sufficient oil/ghee.
Once oil is hot, add tikkis one by one and fry on medium high heat till it starts to turn light brown.
Now here, if you want to make ahead and use later, you can take out on a kitchen towel, cool completely and store accordingly.
Before serving, again heat oil in a pan or use same oil, and fry once again till golden brown in color.
Take out on a kitchen Towel and assemble for chaat.