Preheat your broiler to high, positioning a rack about 6 inches below the heat source. This high temperature will help char the tomatillos and enhance their flavor.
Line a rimmed baking sheet with foil to make cleanup easy. Place the halved tomatillos, onions, garlic cloves, and peppers on the baking sheet. Drizzle everything with 1 tablespoon of olive oil and toss to coat evenly.
Arrange the cut side of the tomatillos facing down. Broil for about 5 to 7 minutes, or until the tomatillos start to char in spots. Keep an eye on them and flip the peppers and garlic halfway through to ensure even charring.
If anything, such as the peppers or tomatillos, becomes too charred, remove them from the oven before the rest are done. Alternatively, for a smokier flavor, you can char the vegetables on a grill.
Once cool enough to handle, chop off the stems of the peppers and remove the seeds. Save the seeds if you want to add more heat later, but don’t add them to the blender just yet.
Add the seeded peppers, along with all the contents from the baking sheet—including any remaining juices—to a blender. This step ensures that all those lovely flavors get incorporated into the salsa.
Add the fresh cilantro, lime juice, cumin, salt, and coriander to the blender as well. Pulse or puree the mixture until it reaches your desired consistency, scraping down the sides as needed.
Once blended, taste your Salsa Verde and stir in the reserved seeds gradually if you’d like it spicier. Season with additional lime juice and salt if desired to suit your taste.
For the best flavor, chill the Salsa Verde in the refrigerator for at least 2 hours before serving. This resting time allows the flavors to meld beautifully. If it thickens too much in the fridge, simply stir in a little water to reach your desired consistency.
Store your Salsa Verde in an airtight container in the refrigerator, where it will keep well for about 7 to 10 days, making it a great make-ahead option!
