Grill the tomatoes, onion, and peppers until the tomatoes are marked and warm through, the onion is slightly browned and soft, and the peppers skin has blistered and browned. Remove them from the heat and cool until they can be handled easily. Gently remove the skin from peppers. Chop all veggies into small pieces (about 1/3 inch dice) and put them in a small bowl.
Add the cilantro, lime juice and seasoning. For more heat, add more jalapeno or a dash of cayenne.