Step 1

Heat the broiler to high with a rack 4 inches from the element. On a broiler-safe rimmed baking sheet, mound together the onion wedges and jalapeños. Drizzle with 1 tablespoon oil and sprinkle with ½ teaspoon salt; toss to coat. Arrange in an even layer and broil until charred and tender, 10 to 15 minutes, flipping once halfway through. Set aside to cool.

Step 2

When cool enough to handle, chop the jalapeños; add them to a medium bowl. Trim and discard the root ends from the onion wedges, then chop and add them to the bowl. Stir in the tomatoes, cilantro and chipotle chili, then let stand at room temperature for 30 minutes. Stir in the lime juice and remaining 1 tablespoon oil. Taste and season with salt and pepper. Serve right away or refrigerate in an airtight container for up to 3 days; bring to room temperature before serving.