Place potatoes in a Pressure cooler; add water to cover. Heat until pressure relief rattles. Reduce heat to keep a constant rattle; cook,for 3-5 minutes or until tender. Meanwhile, place oil and garlic in a small food processor; process until blended.

Drain potatoes; return to pan. Mash potatoes, gradually adding cream, butter, salt, pepper and enough milk to reach desired consistency. Stir in green onions. Serve with garlic olive oil and, if desired, cheese