1. Adjust oven rack 6 inches from broiler element and heat broiler. Line rimmed baking sheet with aluminum foil. Toss half of tomatillos with vegetable oil and transfer to prepared sheet. Broil until tomatillos are spotty brown and skins begin to burst, 7 to 10 minutes. Transfer tomatillos to food processor and let cool completely.

2. Halve remaining tomatillos and add to food processor with broiled tomatillos. Add onion, jalapeño, cilantro, lime juice, garlic, and 1/4 teaspoon salt. Pulse until slightly chunky, 16 to 18 pulses. Transfer to salsa bowl and let stand at room temperature for 15 minutes. Stir in olive oil and season with salt and sugar to taste. Serve.

Makes 2 cups