Preheat your oven to 400°F (200°C). Cut off about ¼ inch from the top of the head of garlic to expose the cloves. Drizzle with olive oil and sprinkle with salt. Wrap in aluminum foil and roast for 35-40 minutes until soft and golden brown.
Core and quarter the tomatoes, roughly chop the onion, and remove the stems, seeds, and membranes from the jalapeños. Place these ingredients in a food processor along with the roasted garlic cloves, cilantro leaves, lime juice, salt, cumin, and black pepper.
Pulse the mixture until you reach your desired consistency. Taste and adjust seasonings as needed.
Transfer the salsa to an airtight container and refrigerate for at least an hour before serving.
