1. Combine garlic and lemon zest and juice in small bowl; set aside for at least 15 minutes. Measure out 2 tablespoons artichoke hearts, chop coarsely, and set aside for garnish.

2. Pulse beans, reserved bean liquid, remaining artichoke hearts, scallion whites and light greens, parsley, ground fennel, 3/4 teaspoon salt, cayenne, and lemon 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 artichoke hearts and scallion greens. Drizzle with oil and serve.

Makes about 2 cups

URL: http://www.cooksillustrated.com/recipes/detail.asp?docid=37010