Cheddar-topped Shepherd's Pie

There's sharp cheddar added to the mashed potatoes for a snappy topping. Both filling and topping can be made up to a day ahead and refrigerated separately. We made this last night and it was great comfort food!

Ingredients:
2 lb. baking potatoes (about 4), peeled and thinly sliced
coarse salt and ground pepper
1 Tbsp vegetable oil
6 medium carrots, halved lengthwise, quartered if large and thinly sliced
6 celery stalks, thinly sliced
1 large onion, chopped
1/2 tsp dried thyme
1/4 cup all-purpose flour
1/4 cup tomato paste
2 lb ground beef chuck
1 cup whole milk
1.5 cups shredded sharp white cheddar (6 oz)

Directions:
1. Preheat oven to 450 degrees. Place potatoes in a large saucepan, and cover by 1 inch with salted water. Bring to a boil; reduce to a simmer. Cook until potatoes are easily pierced with the tip of a paring knife, 15-20 minutes.
2. Meanwhile, heat oil in a 12-inch skillet over medium-high heat. 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.
3. Drain potatoes; return to pan. Cook over medium heat, stirring, until liquid has evaporated and a thin film covers bottom of pan, about 1 minute. Remove pan from heat; add milk and 1 cup cheese. Mash until smooth, season cheddar-potato topping with salt and pepper.
4. Pour beef filling into a 13-by-9 inch baking dish. Drop dollops of topping 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.

Serves 8; 558 calories per serving.