Step 1Heat the oven to 400 degrees.
Step 2Fill a large bowl with water and add the lemon juice. Peel off the outer leaves of the artichokes until you reach the tender pale green leaves in the center. Use a paring knife to cut most of the stems off each artichoke, leaving about 1 inch. Pare off the tough outer skin of the stems. Cut 1/4 inch off the tip end of each artichoke, cut them in half and place the halves in the lemon water. After you've trimmed all the artichokes, drain them, pat dry and place them in a large bowl. Add the sliced lemons.
Step 3Stir in the salt, pepper to taste and the herbes de Provence. Pour in the olive oil and combine. Spoon the artichokes into a large roasting pan. Arrange the lemon slices over the artichokes and cover with foil. Bake for 20 minutes. Stir in the olives, cover and roast until the artichokes are tender, another 20 minutes.