Heat a large, dry cast-iron skillet over medium heat. Add the whole tomatoes, poblano and jalapeno halves, onion wedges, and garlic cloves. Cook until each ingredient is charred and blistered, rotating and flipping as needed to get charred on all sides. Some ingredients will finish before others, just remove each one from the skillet to a plate as they finish charring/blistering. The entire charring process should take about 15 minutes or so.

Next place the charred peppers, onion, and garlic in a blender carafe. Then add the lime juice, olive oil, salt, pepper, and cumin. Cover the blender carafe tightly and give the mixture 2 quick pulses. Now add the charred tomatoes and cilantro leaves, cover tightly, and give 1 quick pulse. Examine the texture. If desired, continue to pulse, 1 pulse at a time, until you reach your desired consistency. I use a high-power Vitamix blender and like to have a bit of chunky texture to my salsa, so it only takes me 1-2 pulses after the tomatoes and cilantro are added. Note that the tomatoes will be very soft after roasting for 15 minutes, so it does not take very much to blend them. Also, if your blender is not as powerful, you may need to pulse more.

Season to taste. Enjoy the salsa warm, with tortilla chips for dipping. To keep the salsa warm, you can place it in a warmed serving bowl or small crockpot. We also add the salsa to a small pan and set it over low heat on the stovetop, super casual.