Shepherd's Pie with Garlic Mashed Potatoes

preheat oven to 475 Take 2 bulbs (whole head) of garlic and drizzle with olive oil and wrap in aluminum foil and cook for 1 hour in oven ; when garlic is cool clip ends of pointed side of garlic and squeeze out paste; mix prepared mashed potatoes with roasted garlic and set aside; cook meat and drain; coat same skillet with cooking spray and add garlic , onions and vegetables until onion is tender; add beef broth and bring to a boil; simmer 5 minutes or until vegetables are tender; ; preheat oven 450 mix vegetable juice and cornstarch and pour over vegetables and continue to simmer until desired thickness adding beef, worcestershire sauce, rosemary, salt and pepper; transfer to casserole and top with mashed potatoes. sprinkle top with parmesan cheese and cheddar cheese and bake for 15min untill golden brown.