Step 1

Heat a large cast iron skillet or a heavy-bottomed skillet over high heat. Add the tomatoes and the chiles to the pan and char on all sides, rotating the vegetables occasionally until blackened. This can take about 6 minutes for the chiles and 10 to 15 minutes for the tomatoes. The tomato skins should begin to pull away from the flesh and the chiles will look blistered.

Step 2

Transfer the chiles to a cutting board and allow them to cool. Place the tomatoes, including any charred skin that has completely fallen off, in the bowl of a food processor or blender. Pulse a couple of times for about 10 seconds or until the tomatoes are blended but with a few small chunks for texture.

Step 3

Transfer the blended tomatoes to a bowl. Cut the charred chiles in half lengthwise and remove the stems and seeds. You can remove the ribs if you don’t like the salsa too spicy. Chop the chiles into small dice.

Step 4

Mix the chiles, onions and cilantro with the tomatoes until combined. Stir in the lime juice and salt. Taste and season with additional lime juice and salt, if needed. Cover and refrigerate until cooled. Serve with chips.