Preheat the broiler. Toss together the tomatillos, poblanos, onion, black pepper, 1 tablespoon of the oil, and ¼ teaspoon of the salt to coat on a rimmed baking sheet. Broil, 5 inches from heat, turning occasionally, until the peppers are blistered and charred in spots, about 8 minutes. Cool completely.
Brush the skins off the poblanos with a paper towel; pulse with the remaining roasted vegetables and ¾ cup of the cilantro in a food processor until coarsely chopped. Stir in the lime juice, the jalapeño, the remaining cilantro, 7 tablespoons oil, and 1¾ teaspoons salt. Serve immediately, or refrigerate in an airtight container up to 3 days.