Give them a good rinse in some vegetable wash to remove the sticky residue. Occasionally, the sticky stuff might be stubborn to remove and in that case you can wipe them down with a little white vinegar.
Place the baking sheet a few inches below the broiler and roast for 4-5 minutes until the tomatillos start to char or become blackened in some spots. Flip everything over and roast for an additional 4-5 minutes.
In a food processor or blender add the rest of your ingredients; red onion, cilantro, garlic, lime juice, cumin, and salt along with the tomatillos, jalapeño (start with half of the pepper and add more based on your heat preference) and any of the juices from the baking sheet.
Scoop into a bowl and serve with your favorite tortilla chips, of course! While great with chips, this salsa can go with almost everything – from tacos and quesadillas, to grilled meats and fish, and even eggs!