Preparation Set strainer over large bowl. Line strainer with 2 layers of cheesecloth, allowing 4 inches to extend over sides of strainer (do not let strainer touch bottom of bowl). Spoon yogurt into strainer. Fold overhanging cheesecloth over yogurt. Chill overnight (liquid will drain out and yogurt will thicken; discard liquid). Finely chop green onions in processor. Add half of roasted peppers and chipotle chilies. Process until peppers are finely chopped, scraping down sides of bowl occasionally. Add 1/2 cup plus 2 tablespoons drained yogurt (reserve any remaining yogurt for another use), mayonnaise and herbes de Provence. Process to blend. Add remaining peppers. Using on/off turns, process until peppers are coarsely chopped. Season with salt and pepper. Transfer to bowl. Chill at least 30 minutes and up to 1 day to blend flavors.
Preparation Set strainer over large bowl. Line strainer with 2 layers of cheesecloth, allowing 4 inches to extend over sides of strainer (do not let strainer touch bottom of bowl). Spoon yogurt into strainer. Fold overhanging cheesecloth over yogurt. Chill overnight (liquid will drain out and yogurt will thicken; discard liquid). Finely chop green onions in processor. Add half of roasted peppers and chipotle chilies. Process until peppers are finely chopped, scraping down sides of bowl occasionally. Add 1/2 cup plus 2 tablespoons drained yogurt (reserve any remaining yogurt for another use), mayonnaise and herbes de Provence. Process to blend. Add remaining peppers. Using on/off turns, process until peppers are coarsely chopped. Season with salt and pepper. Transfer to bowl. Chill at least 30 minutes and up to 1 day to blend flavors.