First of all, peel off the garlic. Also, peel and quarter the onion. Now take jalapeno and take out the seeds and ribs. Quarter the tomatoes if they are ample sized, otherwise, keep them as it is.
Get a baking sheet and keep garlic, green tomatoes, onion, and jalapeño on it. For 4 to 5 minutes, broil all these on high to the point they start to become black. Flip them once and also rotate the veggies. Another time, broil for 4 to 5 minutes.
Shift everything into a food processor. Only use the ½ of the jalapeño. Add the kosher salt, cilantro, and lime juice. Until you get the desired consistency, pulse it well. Check the taste, and see if you want to add an extra ½ of jalapeño. Keep the salsa at room temperature until serving.