Modern Turnips in Butter

From A Feast of Ice and Fire by Chelsea Monroe-Cassel and Sariann Lehrer.
Ingredients:
3 large turnips, peeled and cut into similar-size pieces
1 c. milk
3 sprigs fresh thyme
2 cloves garlic, peeled and chopped
1/4 c. (1/2 stick) unsalted butter, cut into cubes
Salt
Black pepper

Add the turnips, milk, and thyme to a large saucepan and simmer over medium heat for 20 minutes, or until the turnips are tender enough to stick a fork through with little resistance.
Drain the turnips, reserving the cooking liquid. Discard the thyme sprigs. Puree the turnips using a potato masher, immersion blender, or regular blender. Melt in the butter, add the chopped garlic, and continue blending. Add ~1/2 cup of the reserved cooking liquid and combine until a uniform consistency is achieved.
Season with salt and pepper and serve.
Serves 4.