01 -
Preheat the oven to the broil setting. Line a baking sheet with aluminum foil for easy cleanup.
02 -
Place the quartered tomatoes, jalapeño peppers, separated layers of red onion, and garlic cloves on the lined baking sheet, spreading them out in a single layer.
03 -
Broil the vegetables for 9 minutes. Then flip all the vegetables over and continue broiling for an additional 10-15 minutes, or until the tomatoes and jalapeño peppers begin to brown and blister. Watch carefully to prevent burning.
04 -
Transfer the roasted vegetables to a food processor. Add the fresh cilantro leaves and kosher salt.
05 -
Process the mixture until smooth or to your desired consistency. Allow the salsa to cool to room temperature before serving for the best flavor.