Bring a large amount of salted water to the boil with a slice of lemon. Break the stems of the artichokes, cut off the top leaves (optional) and use scissors to cut the pointed outer petals.
Rub the artichoke with the lemon to prevent oxidation.
Boil the artichoke for 15-20 minutes (depending on the size) until the heart is tender. When ready, remove the artichokes and place them upside down on a wire rack to cool.
Prepare the vinaigrette
Whisk together the Dijon mustard with vinegar, salt, and pepper. Slowly whisk the oil into the mustard mixture as you would make a mayonnaise. Season to taste.
Use your finger to gently open the inner petals of the artichoke and remove the ‘hairy’ centre. Pour the vinaigrette in the centre and serve.
Notes
Keep the artichoke stems for another recipe such as cream soup or cream sauce.