> 2 lbs turnips
> 1 large russet potato (about 3/4 lb)
> 2 cups low-fat milk
> 1 sprig rosemary
> 2 cloves garlic
> 3 tbsp olive oil
> 1 tbsp unsalted butter (optional)
Peel the turnips and potato. Cut both into 1-inch chunks. Add to a medium pot with the milk, rosemary, and garlic. Add enough water to cover turnips and potato. Season well with salt and pepper.
Bring to a boil on high. Reduce heat and simmer 15–20 min., until turnips and potato are fork-tender. Halfway through, remove and discard rosemary.
Drain the turnips and potato, reserving 1 cup cooking liquid. Transfer turnip mixture and ½ cup cooking liquid to a food processor or blender along with the oil. Purée until smooth, adding more liquid if needed. Season with salt and pepper. Top with the butter, if desired.