Add garlic to the bowl of a food processor fitted with a metal blade. Puree until garlic is minced. Add mayonnaise, crème fraîche, mustards, horseradish, and lemon juice. Puree for 1 minute. Season with salt and pepper, and puree for 10 seconds. Transfer to a serving bowl and garnish with chives.

Add garlic to the bowl of a food processor fitted with a metal blade. Puree until garlic is minced. Add mayonnaise, crème fraîche, mustards, horseradish, and lemon juice. Puree for 1 minute. Season with salt and pepper, and puree for 10 seconds. Transfer to a serving bowl and garnish with chives.