MAKES ABOUT 1 CUP

Although no bouillabaisse is authentic without this garlicky Provençal paste (the name means rust in French, a reference to its color), there is no definitive recipe for rouille. Some traditional versions call for bread soaked in fish stock, or for a potato cooked along with the fish; some specify cayenne peppers, some mild red peppers; Lulu Peyraud's version adds a gently poached monkfish liver. By comparison, this preparation seems simple.

1 pinch saffron threads
2 tbsp. Fish Stock
4 garlic cloves, peeled and minced
1 cup Mayonnaise
1⁄2 tsp. sweet paprika
Pinch cayenne
Salt

1. Crumble saffron threads in stock in a food processor or mortar. Add garlic and purée, or grind with a pestle, until smooth. Transfer to a bowl and stir in mayonnaise, paprika, and cayenne. Season to taste with salt. (Rouille is best used the same day.)