Dice 1 lemon into 1/4-inch pieces; set aside. Slice the remaining lemon into 1/4-inch-thick slices; set aside.
Heat oil in a large Dutch oven over medium heat. Add onion to pan; sauté 5 minutes or until soft. Add broth and next 8 ingredients (through cinnamon stick); bring to a boil. Cover, reduce heat, and simmer 30 minutes or until vegetables are tender. Add diced lemon and artichokes to pan; simmer 5 minutes. Discard cinnamon stick. Garnish with lemon slices.