Cheddar Topped Cottage Pie
4 cups mashed potatoes (either store-bought or homemade. I likeThe Pioneer Woman's recipe)
Coarse salt and ground pepper
1 tablespoon vegetable oil, such as safflower
6 medium carrots, halved lengthwise, quartered if large, and thinly sliced
6 celery stalks, thinly sliced
1 large onion, chopped
1/2 teaspoon dried thyme
1/4 cup all-purpose flour
1/4 cup tomato paste
2 pounds ground beef chuck
1 1/2 cups shredded sharp white cheddar (6 ounces)
Heat oil in a 5-quart Dutch oven or heavy pot over medium-high. Add carrots, celery, onion, and thyme. Cook, stirring occasionally, until vegetables are tender, 8 to 10 minutes. Add flour and tomato paste; cook, stirring, 1 minute. Add beef; cook, stirring occasionally, until no longer pink, 6 to 8 minutes. Add 1 cup water; bring to a boil, and simmer 1 minute. Set beef filling aside.
Pour beef filling into a 13-by-9-inch baking dish. Mix one cup of cheese into mashed potatoes. Drop dollops of mashed potatoes over filling; spread to edges with a spatula. Using a fork, make decorative peaks; sprinkle with remaining 1/2 cup cheese. Bake until topping is browned and filling is bubbling rapidly, about 20 minutes (if topping and filling were chilled, increase to 35 minutes). Let stand 5 minutes before serving.