Toss the chicken with 1 tsp of the garam masala and 1/2 tsp of the salt. Heat 1 tbsp oil in a 4-quart / 3.8 L Dutch oven (26 cm / 10-inch) over medium-high heat. Brown half the chicken for 3 to 4 minutes, turning once, until golden outside but not cooked through, then move it to a plate. Repeat with the remaining oil and chicken.

Lower the heat to medium. Add the onion and cook for 6 to 7 minutes, scraping up the browned bits, until soft with golden edges. Stir in the garlic, ginger, tomato paste, remaining 2 tsp garam masala, cumin, turmeric, paprika and cayenne, and cook for 1 minute until the paste darkens to brick red and the spices smell toasted.

Pour in the crushed tomatoes, coconut milk, broth and remaining 1/2 tsp salt, and stir. Return the chicken and its juices to the pot and add the chickpeas. Bring to a gentle boil, drop the heat to low, and simmer partially covered for 20 minutes, stirring every 5 minutes. The curry is ready when the sauce coats the back of a spoon and the largest piece of chicken reads 165 F / 74 C and is opaque and firm all the way through with no pink.

Turn the heat off and let the pot sit for 2 minutes. Stir 3 tbsp of the hot sauce into the yogurt in a small bowl, then stir that mixture back into the pot with the lemon juice. Taste and add salt in small pinches. Top with cilantro and do not return the pot to a boil.