01 - Preheat oven to 400°F. Slice the top off the garlic head to expose cloves. Drizzle with olive oil, wrap in foil, and roast for 35 to 40 minutes until soft and golden. Remove and let cool.
02 - Place potatoes in a large pot and cover with cold water. Add a generous pinch of salt. Bring to a boil, reduce heat to simmer, and cook until fork-tender, approximately 15 to 20 minutes.
03 - Drain potatoes thoroughly and return them to the hot pot. Steam for 2 minutes to evaporate excess moisture.
04 - Squeeze roasted garlic cloves from their skins directly into the potatoes.
05 - Add butter, warm milk, and cream to the potatoes. Mash until smooth and creamy, achieving desired consistency.
06 - Season generously with salt and pepper. Taste and adjust seasoning as needed.
07 - Transfer to a serving bowl and garnish with chopped chives or parsley if desired. Serve immediately while hot.