1. In a medium-size saucepan, bring carrots, onion and 4 cups water to a boil over high heat. Reduce heat to medium-low; cook, covered, 15 minutes until vegetables are tender. Add peas and cook 3 minutes. Remove from heat. Drain, reserving 2 cups of the vegetable water. Set aside water and vegetables.
2. Stir beaten egg into prepared mashed potatoes. Set aside.
3. Heat oven to 350 degrees F. Lightly oil a 9 x 9 x 2-inch casserole. In large skillet over medium heat, saute lamb and garlic in oil for 5 minutes. Stir in Worcestershire, thyme, hot-pepper sauce and salt.
4. Add flour to meat mixture and cook, stirring, 1 minute. Stir in the 2 cups reserved vegetable water. Bring to a boil over high heat and cook 1 minute or until thickened. Remove from heat. Stir in carrot mixture. Pour into prepared pan. Spread mashed potatoes evenly over top.
5. Bake at 350 degrees F for 30 minutes or until bubbly and the potatoes are browned.