MASHED POTATO, RUTABAGA AND PARSNIP CASSEROLE WITH CARAMELIZED ONIONS

Mashed Potato, Rutabaga and Parsnip Casserole with Caramelized Onions image

Yield Serves 8 to 10

Number Of Ingredients 9

7 cups canned low-salt chicken broth
3 pounds russet potatoes, peeled, cut into 1 1/2-inch pieces
1 1/2 pounds rutabagas, peeled, cut into 1/2-inch pieces
1 1/4 pounds parsnips, peeled, cut into 1 1/2-inch pieces
8 garlic cloves
1 bay leaf
1 teaspoon dried thyme
3/4 cup (1 1/2 sticks) butter, room temperature
3 large onions, thinly sliced

Steps:

Butter 13 x 9x2-inch glass baking dish. Combine first 7 ingredients in large pot; bring to boil. Reduce heat, cover partially and simmer until vegetables are very tender, about 30 minutes. Drain well. Transfer vegetables to large bowl. Add 1/2 cup butter. Using electric mixer, beat mixture until mashed but still chunky. Season with salt and pepper. Transfer mashed vegetables to prepared dish.
Melt remaining 1/4 cup butter in heavy large skillet over medium-high heat. Add sliced onions and sauté until beginning to brown, about 5 minutes. Reduce heat to medium-low and sauté until onions are tender and golden brown, about 15 minutes. Season with salt and pepper. Spread onions evenly over mashed vegetables. (Casserole can be prepared up to 1 day ahead. Cover and refrigerate.)
Preheat oven to 375° F. Bake casserole uncovered until heated through and top begins to crisp, about 25 minutes.