Preheat oven to 350°F. Line a baking sheet with foil or parchment paper.

Arrange tomatoes, jalapeños, serranos, garlic cloves (with skins on), and onion halves on the baking sheet.

Roast for 12–15 minutes, or until tomato skins begin to split. Remove tomatoes.

Return peppers, garlic, and onions to oven for another 5 minutes until slightly charred.

Let everything cool slightly. Peel garlic and remove stems from peppers.

In a blender or food processor, combine half the tomatoes with roasted onions, garlic, and peppers. Pulse for 5–10 seconds until mostly blended.

Add remaining tomatoes and pulse once or twice for a chunkier texture. Season with salt to taste.

Optional: Stir in chopped cilantro and lime juice before serving.