Chop the onions, carrots and beans finely and set it aside.
Heat 2 tbsp butter in a kadai on medium flame. When it is hot, ass the chopped onions, carrots and beans and saute well and cook for 2-3 minutes
Add the boiled sweet corn kernels and the green peas and mix well. Cook for 2 more minutes.
Add the boiled and mashed potatoes and mix everything well.
Add all the spice powders and the bread crumbs listed under 'For the veggie patty' to the potato mixture. Mix well and mash the mixture and let it cook until there is no moisture left.
Switch off the stove and let it cool down. Now, roll the patty mixture into a log using a cling wrap or aluminium foil.
Secure both ends and place it in the freezer for 30 minutes.
Meanwhile, mix 3 tbsp maida, 2 tbsp corn flour and salt as required. Add some water to form a thick batter. Keep it aside.
Take generous amount of bread crumbs on a plate to coat the patties.
After 30 minutes, cut the veggie patty log into thick discs. Slightly press down the patty discs on all sides to match the size of your burger bun.
Take each patty disc and coat them in the batter on both the sides and then coat them with breadcrumbs. Add some water to the batter to slightly thin it out. Now again, take the crumb-coated patty and dip them in the batter. Coat them on both the sides.
Now, again coat them in the bread crumbs for a double coat leayer.
Heat oil for shallow frying in a pan on medium heat.
Shallow fry the patties evenly on all sides until golden-brown in color.
Drain them onto a plate and set aside.