Maybe try substituting a few ingredients. A chana chaat is healthy because it contains chick peas (protein) and sometimes yogurt, which is also a good source of protein. Potatoes can be fattening, so substitute with sweet potatoes instead. Try sweet potato pakoray. Try baking/grilling things that are typically friend.
Fruit chaat
Make vegetable shami kababs…or make them from ground chick peas. Or from low fat meat like chicken or tuna.