Like all mothers, I am also so concerned about kid's nutritional food habits. Sharing some tips which I usually apply and have succeeded in it too. You can try it, if your kids are not fond of leafy vegetables and vegetables.
1. Take 2 carrots, 1 beetroot and one potato (the ratio can be changed). Cook it in a pressure cooker with some salt. Keep it some time for cooling. Now you can grind it in mixie to make a fine paste. Instead of water, use this paste to mix while making chapatis. Same way add the paste in idli/dosa batter and make pink dosas and idlies. Your kids will really love the pink color chapatis, idlis and dosas.
2. Take a bundle of palak cheera (spinach), clean it and cut it into small pieces. Cook it for one minute and make a fine paste as before. This paste also can be used in the same way to make chapatis, idlis and dosas. Only one difference, the chapatis will be greenish. Spinach is rich with iron, vitamin K and folic acid.
3. I tried the palak paste in one more dish. While making vegetable biriyani, add this paste with the water we use to make biriyani. Rich green and more nutritious veg biriyani is ready. If you use the pink paste(carrot and beetroot) in the biriyani, it will look pinkish. (I couldn't try it. Planning to make it next time).
Note: There wont be any taste difference in the chapatis/idlis/dosas/biriyani. You can keep this paste in refrigerator up to one week time. My son never eats leafy vegetables. But he is fond of this *pista chapati and *pista biriyani. (*A new name I made for these green dishes to convince my kids).