2) Save what you don't use in a small glass jar. It should last in the fridge for 2-3 weeks. It's a delicious addition to marinades, pasta sauces, stir fry sauces, slow-cooker recipes, gravy, etc. We always had a jar of this stuff in our fridge growing up.
3) For the wet masala, in a small skillet over medium-high heat, toast the cumin seeds, cinnamon bark, cloves and peppercorns until fragrant, about 1 minute. Pour into a spice grinder and process until powdered. In a small food processor or blender, combine the toasted spice mix and the rest of the wet masala ingredients. Process until smooth.
4) Place a large (preferably nonstick) pot over high heat and add the oil. When the oil is shimmering, add the onions and serrano pepper. Stirring frequently, saute the onions until golden brown, about 12 minutes. Don't let them burn! Turn the heat down to medium-high if they're starting to burn.
5) Add the ground wet masala, taking care because it will sizzle wildly and steam up your glasses, if you wear them. Stir quite vigorously and turn down the heat if it's bubbling too furiously. Don't wash the food processor bowl yet. Keep stirring, with short pauses, until most of the liquid has evaporated and the masala comes together as one mass, about 2 minutes. Also, you may see little droplets of oil on the perimeter of the masala. That's a good sign!
6) Quickly add the meat and stir, coating the meat in the masala. Stir and cook about 5 minutes until the meat browns.
7) Remember that dirty food processor bowl? Fill it with 230ml of hot water (from the tap is fine), swirl it around so it picks up any leftover masala and pour that into the pot. Add salt and pepper, stir, bring the curry to a boil and then turn it down to a simmer. Cover and cook 30 minutes. Then cook with the lid ajar for another 10 minutes to thicken the gravy slightly. Check the meat at the end of the cooking time; it should be tender and not chewy at all. Adjust the salt if you like and serve over rice or with chapatis (wholemeal griddle bread).