Mash the yolks or force them through a sieve into a bowl.
Add the mustard, salt, and pepper, and mix well.
As when making mayonnaise, very gradually beat in the olive oil a few drops at a time at first. Because the cooked yolks do not enable a stable emulsion like raw yolks do, the mixture curdles
Per 1 fl oz (29.57 mL): Calories, 180; Protein, 2 g; Fat, 19 g (96% cal.); Cholesterol, 50 mg; Carbohydrates, 0 g; Fiber, 0 g; Sodium, 70 mg.