1. Cut the stems from the artichokes and trim off the tough lower leaves. Halve the lemons and rub the bottom of the artichokes with one lemon half to prevent discoloration.
2. Juice the remaining lemon halves and reserve 1 tablespoon juice. Add the remaining lemon juice to a large pot of water and bring to a boil. Put the artichokes in the pan and cover with a plate or smaller pot lid to keep them submerged. Cook the artichokes 25-30 minutes, or until you can easily insert the point of a knife into the stem end.
3. Meanwhile, place the mayonnaise in a small bowl. Crush or grate the garlic into the mayonnaise and stir together with mustard and reserved 1 tablespoon lemon juice. Season with pepper.
4. Remove the artichokes with a slotted spoon and drain in a colander, stem side up. Divide among plates and serve with the garlic mayonnaise.
Per serving: 445 calories, 42g fat, 7g saturated fat, 23mg cholesterol, 528mg sodium, 16g carbohydrate, 8g fiber, 3g sugar, 5g protein