Heat oven to 350 degrees. Cut head of garlic in half across the top, drizzle with olive oil, season to taste with salt and pepper. Wrap in aluminum foil and roast for about one hour until garlic is tender. Remove garlic by squeezing each clove. Set aside. Put potatoes in saucepan, cover with water, season with salt and pepper and boil 15 to 20 minutes until fork tender. Drain. Add salt, pepper, butter, heavy cream and roasted garlic. Use mixer until desired consistency. Garnish with parsley, if desired.