Here, a mix of seasoned yellow-fleshed potatoes and fat cloves of garlic is given the sheet-pan treatment, and the result is greater depth of flavor than the usual potatoes boiled in water.
Once the components are mashed together, you can go two ways: butter and milk and/or cream, or keep them dairy-free by adding vegetable broth and a vegan butter.
Make Ahead: The potatoes and garlic can be mashed, minus their final add-ins, cooled and refrigerated up to 3 days in advance.
Garlicky Roast Mashed Potatoes
4 pounds medium-size Yukon Gold or yellow-fleshed potatoes, cut into chunks