Move your oven rack to the top portion of your oven and preheat to broil.
Place the tomato halves (skin side up), onion slices and garlic onto a rimmed, metal sheet pan.
Slide the pan under the broiler and cook for 6 to 8 minutes or until the skin on the tomatoes has blacken.
Allow to cool until the garlic cloves are safe to handle, then remove their skin and add the tomatoes, onions, garlic, chipotle peppers, adobo sauce, salt, pepper, cilantro and lime juice. Secure the lid and pulse until you've reached a desired consistency.
Taste and check to see if it needs more salt. Then either serve immediately or cover and refrigerate until you're ready to serve.