Preheat oven to 425. Place jalapenos, garlic cloves, and white onion on a baking dish. Roast for 15-20 minutes or until vegetables are soft and tender.
Remove tops of jalapenos. Discard tops.
In a food processor or blender, add roasted jalpapenos, onion, garlic, juice from limes, large bunch of cilantro, olive oil, and salt. Pulse on high until completely smooth.
Cool in refrigerator. Serve when cooled.
