Fry the meat with onion and curry powder. Add a little water from time to time, so that the meat will be tender and the onions soft. Then add two teacupfuls of water. As soon as water boils add the vegetables. Cook slowly together until vegetables are soft. In India this curry is always acidulated, but that is not necessary. It is a good plan, however, to always serve sliced lemon with all curries, as some prefer them sour.