1. Combine garlic and lime zest and juice in small bowl; set aside for at least 15 minutes. Set aside 2 tablespoons corn for garnish.

2. Pulse pinto beans, reserved liquid, remaining corn, scallion whites and light greens, cilantro, 3/4 teaspoon salt, chipotle chili powder, cumin, cayenne, and lime juice mixture in food processor until fully ground, 5 to 10 pulses. Scrape down bowl with rubber spatula. Continue to process until uniform paste forms, about 1 minute, scraping down bowl twice. Add yogurt and continue to process until smooth and homogeneous, about 15 seconds, scraping down bowl as needed. Transfer to serving bowl, cover, and let stand at room temperature for at least 30 minutes. (Dip can be refrigerated for up to 1 day. Let refrigerated dip stand at room temperature for 30 minutes before serving.)

3. Season with salt to taste. Sprinkle with reserved corn and scallion greens. Drizzle with oil and serve.

Makes about 2 cups

URL: http://www.cooksillustrated.com/recipes/detail.asp?docid=37008