PreparationFor artichokes: Combine first 7 ingredients in heavy large saucepan. Working with 1 artichoke at a time, cut off stems and remove all leaves. Scrape out chokes, trim edges of hearts, and add to saucepan; sprinkle with salt and pepper. Bring to boil over medium-high heat. Cover pan and simmer until hearts are tender, about 35 minutes. Using slotted spoon, transfer hearts to plate. Cut hearts into 1/3-inch-thick slices. (Can be made 1 day ahead. Cover and chill.) For dressing: Whisk oil, vinegar, and lemon peel in small bowl to blend; whisk in capers. Season dressing with salt and pepper. For potatoes: Cook potatoes in large saucepan of boiling salted water until just tender, about 15 minutes. Drain potatoes; return to same pan. Add butter and oil; mash until smooth. Season potatoes with salt and pepper. (Can be made 2 hours ahead. Let stand at room temperature. Rewarm before serving.) For fish: Sprinkle fish with salt and pepper. Melt butter with oil in heavy large skillet over medium-high heat. Add artichoke slices to skillet. Sauté until heated through, about 5 minutes. Remove from heat. Using slotted spoon, arrange artichokes in center of each of 4 plates; reserve skillet. Spoon 3/4 of warm potatoes atop artichokes on each plate; tent with foil to keep warm. Return reserved skillet with butter mixture to medium-high heat. Add fish and sauté until just opaque in center, about 4 minutes per side. Arrange fish atop potatoes on each plate. Spoon dressing over fish and serve.
PreparationFor artichokes: Combine first 7 ingredients in heavy large saucepan. Working with 1 artichoke at a time, cut off stems and remove all leaves. Scrape out chokes, trim edges of hearts, and add to saucepan; sprinkle with salt and pepper. Bring to boil over medium-high heat. Cover pan and simmer until hearts are tender, about 35 minutes. Using slotted spoon, transfer hearts to plate. Cut hearts into 1/3-inch-thick slices. (Can be made 1 day ahead. Cover and chill.) For dressing: Whisk oil, vinegar, and lemon peel in small bowl to blend; whisk in capers. Season dressing with salt and pepper. For potatoes: Cook potatoes in large saucepan of boiling salted water until just tender, about 15 minutes. Drain potatoes; return to same pan. Add butter and oil; mash until smooth. Season potatoes with salt and pepper. (Can be made 2 hours ahead. Let stand at room temperature. Rewarm before serving.) For fish: Sprinkle fish with salt and pepper. Melt butter with oil in heavy large skillet over medium-high heat. Add artichoke slices to skillet. Sauté until heated through, about 5 minutes. Remove from heat. Using slotted spoon, arrange artichokes in center of each of 4 plates; reserve skillet. Spoon 3/4 of warm potatoes atop artichokes on each plate; tent with foil to keep warm. Return reserved skillet with butter mixture to medium-high heat. Add fish and sauté until just opaque in center, about 4 minutes per side. Arrange fish atop potatoes on each plate. Spoon dressing over fish and serve.