Position oven rack in top ⅓ of the oven. Preheat broiler. Place onion wedges, garlic cloves (with skins on), lime and jalapeno on a baking tray. Broil for 7 minutes, turning onions and jalapeno halfway through.
Allow the aromatics to cool for 15 minutes. Remove garlic cloves from their skin and juice the lime.
Make Salsa
Place onion, peeled garlic cloves, lime juice, jalapeno, salt, and cumin to a food processor. Pulse for 10-15 seconds.
Add the tomatoes and ¼ cup of the cilantro, pulse for 30-45 seconds to combine. Taste for flavor, add additional salt or mint if needed.
Notes
To reduce heat use only half the jalapeno or remove seeds and veins.
How to Make Salsa without Cilantro- substitute fresh mint or 50/50 mint and fresh parsley.