• Preheat oven to 425°F Prepare a baking sheet with a wire rack set on it. This will keep the artichoke packets elevated so the heat can circulate under and around to cook the artichokes evenly.
• In a large bowl prepare a lemon water bath with the water and juice of 2 lemons. The acid in the water will keep the artichokes from discoloring.
• Use a serrated knife to cut ½-inch off the top of the artichokes so they have a flat top.  Using scissors trim the tips of the artichoke leaves. 
• Drop the trimmed artichokes in the lemon water bath. Working with one artichoke at a time, drain and pat dry with paper towels and brush the entire artichoke with olive oil.  
• Cut two lemons in half and squeeze ½ of a lemon on the top of the trimmed artichoke. 
• Stuff slivered garlic between the top leaves of the artichoke. Add a piece of butter and one or two slices of lemon to the top of the artichoke and Sprinkle with salt
• Double wrap the artichoke with layers of heavy duty foil. Sealing well on top by twisting and pinching foil packet. Continue the process with the remaining artichokes.

Roasting the Artichokes:

• Place foil packets of artichokes on a wire rack set over a baking sheet, in the oven and bake for 45-60 minutes, depending on the size.  
• Test for doneness by unwrapping the foil and pulling a leaf from the center of the artichoke.  If the leaf removes easily or with a little resistance, unwrap and enjoy.  If difficult to remove a leaf, rewrap in the foil and bake for an additional 5-10 minutes.  
• Remove Artichokes from oven. When cool enough to handle, unwrap artichokes and enjoy with Lemon-Garlic Aioli.

For the Garlic-Lemon Aioli:

• In the blending container of a mini-food processor combine the garlic, lemon juice, mustard, and egg yolks. 
• Process in short pulses until smooth.  With the motor running, add the oil in a slow, steady stream and process until smooth and blended. Season with salt and pepper.