Preheat oven to 200°C (400°F). Slice the top off the garlic head, drizzle with olive oil, wrap in foil, and roast for 45 minutes until soft and caramelized.

Place potatoes in a large pot of salted cold water, bring to a boil, and simmer for 20 minutes until fork-tender.

Drain the potatoes and pass them through a ricer or food mill back into the pot over low heat to evaporate excess moisture.

Squeeze the roasted garlic cloves from their skins, mash into a fine paste, and incorporate into the warm potatoes.

Stir in the cubed butter and heavy cream using a wooden spoon until the mixture is completely smooth.

Gradually add the shredded cheese in small batches, beating vigorously in a circular motion. Continue beating and lifting the spoon until the mixture becomes highly elastic and forms long, smooth ribbons.

Season with additional salt and white pepper to taste and serve immediately while the cheese is hot.