Before you start cooking, prep all your aromatics and measure out the spices. Keep everything within arm’s reach of the stove. Also, have 1–2 cups of hot water ready to go; you’ll need it throughout the process to deglaze the pan. I use an electric kettle: just fill it and switch it on while you prep the rest.
Place a heavy-bottomed cooking pot (I use a 4-quart braiser) over medium heat. Add oil and let it warm up. Once the oil is hot (but not smoking), add the bay leaf, cloves, cumin seeds, and cinnamon stick. Immediately follow with the chopped ginger, garlic paste, and green chillies. Sauté everything for 8–10 seconds, stirring constantly to infuse the oil. The spices should sizzle and crisp up slightly, but not change color for too much browning can introduce a bitter note.
Next, add the chopped onions. Cook on medium-low heat for 7–9 minutes, stirring regularly, until the onions turn golden brown (not dark brown). This step is key since it develops both the color and flavor base of your curry, so take your time.
Once the onions are golden, deglaze the pot with about ? cup of hot water. Scrape the bottom to release all the flavorful bits and mix them in. Let the water reduce for about a minute; it should soften the onions further without drying them out completely.
Now sprinkle in the ground spices—coriander, turmeric, red chilli powder, Kashmiri chilli powder, ground cumin, and black pepper. Also add the salt. Stir to coat the onions evenly. Cook this spice mix over low to medium heat for 1–2 minutes, adding small splashes of hot water to prevent sticking and to help the spices toast evenly. You’ll know it’s ready when the masala looks rich and glossy, and the raw spice aroma has mellowed. Your kitchen will smell amazing!
Add the pureed tomatoes and cook down (bhuno) the mixture, stirring regularly until most of the moisture has evaporated and the oil begins to separate. At this stage your masala should look shiny and well-blended.