Step 1

Butterfly the chicken by cutting along the breast bone. Place the chicken skin side up on a on a large cutting board, cover with a piece of plastic and pound to flatten. Season with salt on both sides and set aside.

Step 2

Heat the butter in a large cast iron skillet over medium-low heat. Place the chicken skin side down on the skillet, weight it down with a heavy object, and fry for 20-25 minutes, until the skin is dark golden-brown. Flip and cook for another 20-25 minutes or until the chicken is cooked through.

Step 3

Meanwhile, bring water to a boil in a medium pot. Add the tomatoes and blanch for 1 minute then place in a bowl with cold water and let cool down for a minute. Drain the water and remove skins.

Step 4

Place the skinned tomatoes and the rest of the ingredients in a blender and pulse for 15 seconds. Transfer to a pot, bring to a boil, lower the temperature to low and simmer for 10 minutes. Salt to taste. Remove from heat and let cool down. The sauce can be prepared in advance and stored in a refrigerator.

Step 5

Transfer the chicken to a serving platter and let rest for 5 minutes. Sprinkle with chopped fresh cilantro and serve with the tomato-walnut sauce. You may also garnish the chicken with whole cilantro twigs and slices of red hot chili peppers.