Start by filling a large pot with about 2 inches of water. Place a steamer basket inside if you have one, otherwise the artichokes can sit directly in the water. Bring the water to a boil over medium heat.
While the water heats, prepare your artichokes. Using a sharp knife, cut off the stems flush with the base so they can sit upright. Trim about 1 inch from the top of each artichoke.
Remove the tough outer leaves near the base and use kitchen scissors to snip the sharp tips off the remaining outer leaves.
Gently spread the leaves apart without breaking them and tuck thin slivers of butter and slices of garlic between the leaves, distributing them evenly throughout each artichoke.
Season the artichokes generously with salt and freshly ground black pepper, making sure some seasoning falls between the leaves.
Place the prepared artichokes in the pot, standing upright. Cover with a tight-fitting lid and reduce heat to maintain a gentle simmer.
Steam for approximately 25 minutes, or until the base is tender when pierced with a knife and an outer leaf pulls away easily.
Carefully remove the artichokes from the pot and let them cool slightly before serving.