Prepare artichokes by breaking stem and twist to remove any tough fibers. Trim base to make it stand upright. Trim points from all the leaves and wash well.
Bring a large pot of water to a boil with the lemon slice and bay leaf; add salt and artichokes. Cook for about 25 minutes over medium heat until it can be easily pierced with a knife.
Whisk egg yolks with salt, pepper, and pureed garlic. Slowly add one third of oil a little at a time and whisk to emulsify. When sauce begins to firm and thicken, add a few drops of lemon juice to thin and add remaining oil to desired thickness.
Adjust seasonings and add more lemon juice if needed.
When artichokes are ready, remove from water and let drain upside down on a paper towel. Serve with sauce garnished with parsley. Serves 4.
Approximate Nutrient Analysis per serving (not including salt to taste):
330 calories, 30 g fat, 4.5 g saturated fat, 90 mg cholesterol, 75 mg sodium, 16 g carbohydrate, 7 g fiber, 1 g sugar, 5 g protein