Chef Rick Bayless makes this light and refreshing ceviche recipe that will work wonderfully as an appetizer for an alfresco dinner party or a Sunday afternoon barbecue.
Set a dry skillet over medium heat. Lay in the unpeeled garlic cloves and chiles. Roast, turning frequently, until they are soft and blotchy brown in spots, about 10 minutes for the chiles and 15 minutes for the garlic. Cool until easy to handle, and then slip the skins off the garlic, pull the stems off the chiles, and roughly chop (no need to remove the seeds). Put them in a food processor along with the cilantro, parsley, oil, and 2 generous teaspoons salt. Process until nearly smooth (it will be pasty). Scrape the mixture into a storage container and refrigerate until serving time.
In a large bowl, whisk together the lime juice and 1/2 cup of the herb seasoning. (Cover and refrigerate the remainder for another preparation.) Add the fish and cucumber, and stir to combine. To blend the flavors, cover and refrigerate for 1/2 hour (for best results, no more than 1 hour). Taste and season with a little more lime juice or salt if needed, then gently stir in the avocado (save a little for garnish if you want). Serve on plates or in martini glasses lined with lettuce leaves.