Heat oil in a deep pan. Add onion and French beans and sauté for a minute. Add carrot and salt and continue to sauté. Add green and red capsicums and continue to sauté till all the vegetables are slightly softened. Transfer them into a bowl.Add pickled jalapenos and mix. Grate the boiled potatoes into the bowl. Adjust salt and mix all the ingredients well together.
Add half the white sauce and mix. Add half the bread crumbs and mix well.
Spread the remaining white sauce on a plate and keep the remaining bread crumbs on another plate.
Divide the mixture into twelve equal portions and shape them into croquettes.
Create an indentation in the middle of each and place a stick of mozzarella. Close up the edges and roll to enclose the cheese completely.
Roll the croquettes in the white sauce and then in the bread crumbs.
Arrange the croquettes on a plate, cover with cling wrap and freeze to be used when required.
Just before serving, heat sufficient oil in a pan and deep fry the croquettes till golden. Drain on absorbent paper and serve hot.