Rouille is a red chile pepper mayonnaise, traditionally served as an accompaniment to fish stews. Try this roasted pepper version on grilled or steamed fish or as a dip for raw fennel.
Combine garlic, water and saffron in a small saucepan. Cover and cook over very low heat just until steaming, about 2 minutes. (Alternatively, in a small microwave-safe bowl, combine garlic, water and saffron. Cover with plastic wrap, prick with a knife to vent and microwave on medium for 1 minute.) Remove from heat and let stand for 2 minutes.
Combine garlic mixture, roasted red peppers, mayonnaise, salt and cayenne in a blender or food processor; blend until smooth. Transfer to a serving bowl.