Thoroughly rinse the artichoke in cold water, and open the petals a little so that the water gets inside. Cut the tips of each petal, then slice about an inch off the top of the artichoke, and cut the stem of the artichoke. Rub the bottom and top with lemon juice to prevent it from browning.
Fill a medium-sized pot with water, enough to cover the artichoke, and bring it to a boil. Add artichokes, lemon slices, garlic clove, and bay leaf into the pot and leave to simmer on medium heat. Cook for about 30 to 35 minutes until the outer leaves can easily be pulled off.
To make the dip, mix olive oil, garlic, and lemon juice in a small bowl.
Serve the artichoke with the lemon dip on the side. Peel each petal off and dip the white fleshy end into the dressing.