Preheat oven to 375 degrees. Prepare the artichokes by trimming off the tops of the leaves and cut them in half. Cut off the white, fibrous hairs and inner purple leaves.
Place a piece of aluminum foil under each half, and drizzle them with olive oil. Cover each half with a slice of lemon, sprinkle with salt and pepper, then wrap up the artichoke halves in foil. Bake for 45 minutes.
Whisk all the aioli ingredients together, olive oil last. Drizzle on top of artichokes.