Preheat oven to 400 F.
Remove first few layers of dark green outer leaves until the tender yellowish leaves appear. Cut off the top 1/3 of the artichoke to remove the tough ends. Use a vegetable peeler to remove the tougher outer layer of the stem. If desired, cut in half. Note: Small baby artichokes do not have the prickly choke at the center and can be eaten whole. If unsure, cut the artichoke in half and remove any choke. Toss trimmed artichokes with lemon juice to prevent browning due to oxidation.
In a small bowl, whisk together oil, vinegar, garlic, salt and pepper.
Lay artichokes in a single layer in a 10 inch cast iron skillet or shallow roasting pan. If cut, place cut side up. Drizzle oil and vinegar mixture over artichokes. Place in preheated oven for 20 to 30 minutes until tender. Note: to check for tenderness, insert a knife into base of stem. If it slides in easily, the artichokes are done.