Step 1

Place onions, chile peppers, ginger, and garlic in a blender with a splash of water. Blend into a smooth paste; season with salt and pepper.

Step 2

Heat oil in a large, high-sided pan over medium heat. Cook paste until slightly browned, about 5 minutes.

Step 3

Heat a small skillet over medium-low heat. Add Madras curry powder; cook and stir until fragrant, 2 to 3 minutes. Mix into the paste.

Step 4

Cook and stir chicken in the spice paste mixture until browned, 5 to 10 minutes. Pour in tomatoes. Fill the tomato can halfway with water and pour in too. Simmer over medium-low heat until liquid is reduced, about 50 minutes. Season with salt and pepper. Scatter cilantro on top.