In a large saucepan or Dutch oven, over medium heat, add the oil. When the oil is hot, add the onions. Season with salt and pepper. Saute for 4 minutes. Add the fennel. Season with salt and pepper. Continue to saute for 4 minutes. Add the artichokes, orange zest and fish stock. Bring to a boil, reduce to a simmer and cook for 20 minutes. Add the tomatoes, Swiss chard and potatoes. Simmer for 10 minutes.
Season the fish with salt and pepper. Lay the fish in the simmering liquid. Cook for 5 minutes, or until the fish is flaky. Stir in the parsley.
To serve, lay a couple of the croutons in the center of each serving bowl. Ladle the soup over the croutons. Drizzle the Rouille over each serving. Serve immediately.
In a food processor, combine all of the ingredients, except for the oil. Puree until smooth. With the machine running, slowly add the olive oil. Season the emulsion with salt and pepper.