Once you have measured out the spices, take a close look and clean and pick out any small stones, debris etc. Roughly break spices like whole red chilli, bayleaves, cinnamon stick into smaller pieces. Note- De seed the red chillies if you prefer. Tip - Having all the spices roughly of the same size makes sure that no burning happens while we roast since we are not roasting the spices individually.
Add the spices to a pan. Any kind of pan- cast iron or stainless steel or non stick would work. Start spices in a cold pan. Place the pan on the stove on a low flame. Stirring constantly, lightly roast the spices for 5-7 minutes only. Roasting awakens the oils in the spices thereby enhancing their aroma and potency.Tip- Roasting a lot will take away the aroma of the garam masala and taste wise, it may become bitter.
Once the spices are roasted, take the pan off the stove and immediately transfer the spices to a plate to cool completely.Note - The spices are still warm and continue to roast even after you take them off the heat. Dont leave them in the pan to cool down (they will over toast).
Transfer cooled spices to a dry grinder (I use my coffee grinder). Grind to a fine powder in intervals of 30-40 seconds. Make sure to pause and scrape the sides of the jar for even grinding.Tip -Avoid grinding the spices for too long at once on high speed else they start releasing their oils and become sticky.
Store your homemade garam masala in an airtight container in a cool, dark place to preserve its freshness and flavor. The shelf life is up to 3 months. Always use a clean and dry spoon to scoop to avoid contamination and bacterial growth due to moisture.Tip - Always fill your spice containers loosely. Avoid pressing down or over stuffing the containers because that may cause the spice powder to become caked (due to oils in the spices).
Notes
Make sure to use fresh spices to make this homemade spice blend.
Depending on the quality of spices, the color of garam masala will vary.
You could run the ground masala through a sieve if you prefer very fine ground spice blends.
Use sparingly in your recipes. Garam masala has a lot of vibrancy. I usually start with ½ teaspoon of garam masala and taste before adding more. If too much Garam masala is added, it can spoil the taste of your dish.