Set the oven temperature to 400°F and wait until it is heated.
Fill a large pot with water and bring it to a boil. Add salt and 1 tablespoon of lemon juice to the water.
Remove the hard outer leaves of the artichokes until you reach the soft yellowish ones inside. Cut off the top third of each artichoke and save it for making stock later.
Peel off any hard leaves and the outer layer of the stem with a vegetable peeler. Remove and throw away the hairy part in the middle of each artichoke (this is called the "choke").
After boiling the artichoke hearts that you have prepared for 8 to 10 minutes, drain them and pat them dry with paper towels.
Combine the olive oil, dried artichoke hearts and garlic cloves in a large bowl and mix well. Spread them on a baking sheet in a single layer and sprinkle with salt and pepper.
Toss the artichoke hearts occasionally and roast them until they become crispy and golden brown, which should take about 25 to 30 minutes.
Squeeze the garlic cloves out of their skins and into a small bowl. Mash the cloves with a fork until smooth. Stir in the mayonnaise and the remaining 1 tablespoon lemon juice. Season with salt and pepper.
Enjoy the crunchy artichoke hearts right away, along with the creamy garlic mayo as a dip.