Heat oil in a pan. Add cumin and mustard. When they begin to splutter, add hing.
Add onions and fry until transparent. Add tomatoes and sprinkle salt, turmeric.
Cook until the they turn completely mushy and soft.
Add curry leaves, chopped carrots and beans. Stir fry for about 3 minutes.
Cover and cook on a low flame. Keep stirring and cook covered until the veggies turn soft. I did not add water since the vegies i used were very fresh and tender. If the veggies do not get cooked, you can sprinkle little water and cook until done.
Add garam masala, coriander powder and red chili powder. Mix well and cook covered for 2 to 3 minutes for the flavor of garam masala to come out.
Garnish beans carrot curry with chopped coriander leaves. Serve with plain rice or chapatti.