Heat one tablespoon oil in a non-stick pan, add garlic and sauté for ten to fifteen seconds.
Add green and yellow zucchini, mix well and sauté for two minutes.
Add salt, mix well and sauté on high heat till the vegetables are done.
Place mashed potatoes in a mixing bowl, add the sautéed vegetables and mix well.
Add red chilli powder, cumin powder, one-fourth teaspoon chaat masala, garam masala powder, coriander leaves and half cup breadcrumbs and mix well.
Divide the mixture into eight equal portions and shape them into tikkis. Coat the tikkis with breadcrumbs and dust off excess.
Heat oil in a non-stick pan, place the tikkis in it and shallow-fry, turning sides, till evenly done on both sides.
Sprinkle chaat masala on top and serve hot.