Heat oil in pan,add onion julien in it and fry
When done keep aside to cool and crisp
Take fish in mixer jar, Add chopped garlic, Chopped green chillies and grind it
After grind transfer in a bowl and add chopped spring onion green part, egg, chopped onion and lemon zest, lemon juice, Crushed mustard seeds, red chilli powder, black pepper powder, Add mustard sauce and salt to taste,Now mix well
Now take a batch of mixture filled centre with already crisp and cool Caramel onion and cover all sides nicely
Now make all patties like this and keep aside for next preparation
For Burger Sauce,Take mayonnaise,Add mustard sauce,Add some Caramel onion, Chilli flakes, lemon juicein a bowl Now mix well
Now take slurry made with corn flour and water
Now take a patties dip in slurry,coat with corn flakes crumbs
Now drop on hot oil to cook
When one side done flip it to cook and crisp
Now sprinkle some grated cheese over the top and cover to melt it
When done keep out from oil and keep aside
Now take burger bun,devide in to half and spread Burger sauce in it
And now arrange one by one onion,tomato,and cheese slice in it and keep other half on top
Now Centerdfilled caramelized onion burger is ready to serve, serve hot for more taste
