Boil and shred chicken. Keep aside. Boil five cups of water with half a teaspoon of salt and one teaspoon oil. Add spaghetti and cook till al-dente. Refresh in cold water, drain and spread on a plate to cool.
To make egg wash, combine eggs with one tablespoon of water, whisk till light and fluffy and keep aside. To prepare white sauce, heat butter, add refined flour and sauté for a couple of minutes.
Gradually add milk, stirring all the while to avoid lumps. Add salt, pepper powder and mustard powder and mix well. Remove pan from heat. When the sauce cools, add grated cheese, boiled chicken, spaghetti and breadcrumbs and mix well.
Heat sufficient oil in a kadai. Divide the dough into twelve equal portions. Shape into balls, flatten lightly with your hands, dip in egg wash and deep fry in sufficient hot oil till golden.
Drain onto an absorbent kitchen paper and serve hot with lemon wedges.