How to Make It
Bring a saucepan of salted water to a boil. Squeeze the lemon halves into a bowl of water, then add the halves. Working with 1 artichoke at a time, snap off all of the dark green leaves. Using a sharp knife, slice off the top half of the leaves, peel and trim the stem and add to the lemon water. Add the artichokes to the boiling water and cook until just tender, 20 minutes. Drain and let cool.
Meanwhile, in a medium skillet, heat 1 tablespoon of the oil. Add the onion, bell peppers, garlic and thyme and season with salt and pepper. Cook over moderate heat, stirring, until the vegetables begin to soften, 5 minutes. Add the wine, cover and cook over low heat, stirring, until the vegetables are tender, 25 minutes. Transfer to a bowl.
Wipe out the skillet and heat 1 tablespoon of the oil. Add the artichokes and cook over moderately high heat until lightly browned and the outer leaves begin to crisp, about 7 minutes. Season with salt and pepper, add the bell peppers and keep warm.
In a large nonstick skillet, heat the remaining 1 tablespoon of oil. Season the cod with salt and pepper, and cook over moderately high heat, turning once, until lightly browned and slightly firm, about 4 minutes per side. Transfer the cod to plates, garnish with the peppers and artichokes and serve at once.