Cut each potato into eighths and place in large bowl. Add butter, rosemary, thyme, sage, salt and pepper and toss to combine. Scrape onto large parchment paper lined baking sheet. Cut tip of each head of garlic off to expose cloves and place cut side down onto baking sheet. Roast in preheated 425°F (220°C) oven for about 50 minutes or until potatoes are golden and tender. Meanwhile, in saucepan or microwave bring cream and parsley to a gentle boil.
Scrape potatoes into large bowl. Using paper towel, hold onto garlic head and squeeze out cloves into potatoes. Discard skin. Repeat with remaining garlic. Add cream mixture and using potato masher, mash potatoes and cream mixture a few times to create a rough mash. Scrape into 8-cup (2 L) shallow casserole dish to serve. (Make ahead: Cover and refrigerate for up to 1 day. To reheat, cover loosely with foil and bake in preheated 400°F (200°C) oven for about 35 minutes or until knife inserted in centre is hot.).
Gratin Topping: In small bowl, combine cheese and parsley. Sprinkle over top of potatoes and bake in preheated 400°F (200°C) oven for about 5 minutes or until golden and melted. 8 to 10 serving. Preparation time 15 minutes, cooking time 55 minutes.
Real Cream Recipes.