In a saucepan, heat the oil. Add the onion, garlic and <em>lardo</em> and cook over moderate heat, stirring, until softened, about 10 minutes. Drain the artichokes; discard the lemon. Add the artichokes to the saucepan, cover and cook over moderately low heat, stirring, until almost tender, about 10 minutes. Add the white wine, cover and simmer over moderately low heat until tender, about 5 minutes. Season with salt and pepper.