This is an easy way to add a new twist to your mashed potatoes. Turnips add an interesting spicy flavor and the carrots add some nice color and a bit of sweetness. You can make this in advance and place in a covered casserole dish, keeping it in a warm oven at about 200 degrees.
Place all of the vegetables in a stockpot with about 2 inches of water along with the bouillon cubes. (You may choose to place the carrots in first and cook for about 5 minutes before adding the potatoes and turnips, as the carrots take longer to cook.) Cook over medium heat for about 20-30 minutes until all vegetables are tender, and drain thoroughly.
Mash the vegetables together in a large bowl. Add the half-and-half, butter, salt, and pepper. Taste and adjust seasoning. Use a whisk to get the lumps out and smooth out the texture. Garnish with sprigs of fresh parsley or thyme, if using. Serve.