Cut the tops from the garlic heads, nestle into a baking tray, drizzle over 2 tsp olive oil, tightly wrap the tray in foil and bake at 200ºC for 40-45 mins until golden. Cool, then remove cloves from the peel and gently mash with a fork.
Boil potatoes in salted water until soft. Drain well, add milk, cream and butter, mash roughly then fold through mashed garlic. Season to taste.
Spoon into a serving bowl and scatter with parsley to serve.