It is not required to be made at home especially in India. It is so easily available around that you would hardly want to invest your time an energy. However, going by the sub standard flavours coming primarily from the need to be competitive it is always worth trying it once at home. The other advantage is that you can adjust the taste as per your requirement. Some like their bhaji spicy others prefer tangy. I prefer a bit of both.
1 cup red cry chilli (I used Kashmiri colorful+ Bedgi - spicier)
1/2 cup coriander seeds
1/4 cup cumin seeds
1 tspn cloves
1/4 cup dry mango powder
1 tspn black pepper
4 tspn fennel seeds
2 sticks of cinnamon
1 tspn garam masala powder (optional)
1) Dry roast each ingredient (except garam masala) separately in a non stick pan
2) Let them cool down completely
3) Grind them together in a dry grinder. Keep the powder slightly coarse
4) Mix and store in an air tight container.