Stir the yogurt, lemon juice, 1 tablespoon garam masala and 1 teaspoon salt together in a bowl. Add the chicken and turn to coat every piece. Leave it to marinate at room temperature for 20 minutes while you make the sauce.
Make the sauce
Melt the butter in a large, deep skillet or Dutch oven over medium heat. Add the onion and 1/2 teaspoon salt and cook, stirring occasionally, for 8 to 10 minutes, until soft and golden at the edges.
Add the garlic and ginger and cook, stirring, for 1 minute. Stir in the remaining garam masala, the cumin, paprika and turmeric and cook for 30 seconds more, stirring constantly so the spices toast without scorching.
Pour in the crushed tomatoes and scrape up any browned bits from the bottom of the pan. Bring to a gentle simmer, then lower the heat and cook uncovered for 10 to 12 minutes, stirring now and then, until the sauce thickens enough to leave a trail when you drag a spoon through it.
Char the chicken
While the sauce simmers, heat the broiler with a rack about 6 inches below the element. Lift the chicken from the marinade, letting the excess drip off, spread it on a foil-lined baking sheet and discard the leftover marinade. Broil for 8 to 10 minutes, turning once, until charred in spots; it finishes cooking in the sauce.
Finish
Stir the cream into the sauce, then add the chicken and any juices from the baking sheet. Simmer gently for 5 minutes, until the chicken is cooked through and an instant-read thermometer in the thickest piece reads 165°F (74°C).
Taste and add more salt if needed. If the sauce is thicker than you like, loosen it with a splash of water. Serve over the rice, scattered with the cilantro.
Cook's notes
For deeper flavor, cover the marinating chicken and refrigerate it for up to 24 hours.
No broiler? Brown the chicken in a hot, lightly oiled skillet in two batches, 2 to 3 minutes a side, then finish it in the sauce as above.
For a smoother sauce, purée it with an immersion blender before adding the cream.
For more heat, add 1/4 teaspoon cayenne with the other spices.
Start the rice before the sauce: about 1 1/3 cups of uncooked basmati makes 4 cups cooked.
Keeps, covered, in the fridge for up to 3 days. Reheat gently, adding a splash of water if the sauce has thickened.
RecipeFix originals are written as practical home recipes and editorially reviewed for internal consistency. They are not described as kitchen-tested. Nutrition is not shown unless it is calculated from the final recipe.