Prepare the grill for indirect cooking over medium heat (180° to 230°C).
Brush the cooking grates clean. Lightly brush the tomatoes and onion slices with oil. Grill over direct heat, with the lid closed, until lightly charred all over, 6 to 8 minutes, turning once. Remove from the grill, finely chop, and transfer to a medium bowl. Stir in the remaining salsa ingredients.
Related Grill Skills
Slicing an Onion
In a medium bowl using a fork, coarsely mash the avocados. Stir in the onion and lime juice and season with the salt. Cover with plastic wrap, placing the wrap directly on the surface of the guacamole to prevent it from browning, and refrigerate until about 1 hour before serving.
Related Grill Skills
Preparing Avocados for Guacamole
Chopping an Onion
Grill the chiles over direct heat, with the lid open, until the skins are blackened and blistered all over, 10 to 15 minutes, turning occasionally. (The goal is to char the skins quickly so that you can peel them without the chiles collapsing. You will need chiles with enough structure, even when roasted, to hold the filling.) Place the chiles in a large bowl, cover with plastic wrap, and let them steam for about 10 minutes. Gently peel and discard the skin from the chiles. Leaving the stems intact, carefully cut a slit down one side of each chile to make a pocket and remove and discard the seeds and veins. If you rinse the chiles, pat them completely dry with paper towels.
In a medium bowl combine the cheeses and mix together with a fork. Carefully stuff the mixture into the chile cavities. Brush the chiles with olive oil.
Grill the stuffed chiles, seam side up, over indirect medium heat, with the lid closed, until the cheese melts, 6 to 8 minutes. Gently remove them from the grill with a spatula. Serve warm with the salsa and guacamole.
