1 celery root, peeled and cut into 1-inch pieces (about 2 cups)
3 parsnips, peeled and cut into 1-inch pieces (about 2 1/4 cups)
2 Yukon Gold potatoes, peeled and cut into 1-inch pieces (about 2 cups)
2 garlic cloves, smashed and peeled
Zest of 1 small lemon
1/2 teaspoon chopped fresh thyme leaves
1/4 cup extra-virgin olive oil
1/4 cup freshly grated Parmesan cheese
Don't overture this wintery mix; it should be a bit chunky so you can taste the individual veggies in every bite.
Place the celery root, parsnips, potatoes, and garlic into a large pot. Cover with cold water by an inch and add 2 tablespoons salt. Place over high heat and bring to a boil. Reduce the heat to medium and simmer for 10 to 15 minutes or until all of the vegetables are tender. Drain well and return the cooked vegetables to the pot.
Using a wooden spoon, stir the vegetables over medium heat to remove some of the excess moisture, about 4 minutes. Using a large fork or a potato masher, lightly mash the vegetables. Remove the mashed vegetables from the heat and add 1 teaspoon slat, the lemon zest, thyme, olive oil, and cheese. Mix until well combined. Serve hot.