In a covered large saucepan cook potatoes and garlic in enough boiling, lightly salted water to cover about 15 minutes or until potatoes are tender. Drain in a colander.
In the same saucepan heat milk and oil over medium heat until mixture is bubbly around the edges. Remove from heat. Return potatoes to pan and sprinkle with salt and pepper. Mash with a potato masher or beat with an electric mixer on low speed until smooth. If desired, sprinkle with fresh herbs.