Preparation Cook potatoes in large saucepan of boiling salted water until tender, about 15 minutes. Drain. Return to saucepan; mash. Combine bread cubes, green onions, 1/2 cup milk, and tarama in processor. Process until smooth paste forms. Transfer mixture to bowl. Add 1 whole egg and 1 cup mashed potatoes (reserve any remaining potato for another use); stir to blend well. Cover and refrigerate at least 4 hours and up to 1 day. Lightly beat egg whites and remaining 2 tablespoons milk in medium bowl to blend. Place breadcrumbs on plate. Form 2 tablespoons tarama mixture into ball; press to flatten slightly. Dip into egg-white mixture, then coat on both sides with breadcrumbs. Repeat with remaining tarama mixture. Pour equal amounts olive oil and safflower oil into heavy large saucepan to reach depth of 1 inch. Attach deep-fry thermometer to side of saucepan and heat oil over medium-high heat to 350°F. Working in batches, add tarama croquettes to skillet and fry until golden brown, about 3 minutes per side. Transfer to paper towels to drain. Transfer croquettes to platter. Serve hot, passing lemon wedges separately. Available at Greek markets, specialty foods stores, and some supermarkets.
Preparation Cook potatoes in large saucepan of boiling salted water until tender, about 15 minutes. Drain. Return to saucepan; mash. Combine bread cubes, green onions, 1/2 cup milk, and tarama in processor. Process until smooth paste forms. Transfer mixture to bowl. Add 1 whole egg and 1 cup mashed potatoes (reserve any remaining potato for another use); stir to blend well. Cover and refrigerate at least 4 hours and up to 1 day. Lightly beat egg whites and remaining 2 tablespoons milk in medium bowl to blend. Place breadcrumbs on plate. Form 2 tablespoons tarama mixture into ball; press to flatten slightly. Dip into egg-white mixture, then coat on both sides with breadcrumbs. Repeat with remaining tarama mixture. Pour equal amounts olive oil and safflower oil into heavy large saucepan to reach depth of 1 inch. Attach deep-fry thermometer to side of saucepan and heat oil over medium-high heat to 350°F. Working in batches, add tarama croquettes to skillet and fry until golden brown, about 3 minutes per side. Transfer to paper towels to drain. Transfer croquettes to platter. Serve hot, passing lemon wedges separately. Available at Greek markets, specialty foods stores, and some supermarkets.