Place the garlic and salt on a cutting board and mince together. Transfer the mixture to a food processor fitted with the steel blade. Add the egg yolk, lemon juice, saffron, and red pepper flakes. Process until smooth.
With the machine running, pour the olive oil in a thin, steady stream through the feed tube to make a thick mayonnaise emulsion. Transfer the rouille to a serving bowl and store it in the refrigerator until ready to serve.
*RAW EGG WARNING
Food Network Kitchens suggest caution in consuming raw and lightly-cooked eggs due to the slight risk of Salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly-refrigerated, clean, grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.
Contains Raw Eggs: The Food Network Kitchen suggest caution in consuming raw and lightly cooked eggs due to the slight risk of salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly refrigerated, clean grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell. For recipes that call for eggs that are raw or undercooked when the dish is served, use shell eggs that have been treated to destroy salmonella, by pasteurization or another approved method.