Southwest Gratin Potatoes

In Newark, Delaware, there is a modern, fun and loud steakhouse called Firebird's. Don't expect to get a reservation - they don't take 'em. You just have to go and enjoy the cacophony at the bar, but it's worth the wait! Real wood-fired steaks are accompanied by the most fantastic spicy gratin potatoes. This is my take on them, adding sweet potatoes - and don't skimp on the pepper!1 lb sweet potatoes, 2 medium, peeled
1 lb Yukon gold potatoes, 3 medium, peeled

1 1/2 cups milk
grated fresh nutmeg, about 1/8 tsp

2 Tbsp butter, room temperature
2 Tbsp flour

1 1/2 cup grated Pepper Jack cheese, or cheddar plus 1/4 tsp dried red pepper flakes
2 green onions, sliced

Preheat oven to 375F. Slice potatoes in half lengthwise, and then slice into about 1/8-inch half moons. Tip potatoes and milk into a 2 quart pot. Add the nutmeg. Bring potatoes and milk just to a boil. Immediately reduce to a simmer, stir, and cook another 5 minutes.

Meanwhile, crush together the butter and the flour to form a buerre manié - you can use a fork, but I find my fingers are the best utensils for this! Drain the potatoes into a bowl and return the milk to the pot. Bring just to a boil and whisk in the buerre manié. Whisk to a thick sauce, then add the cheese and onions. Return the potatoes into the sauce and fold together.

Turn potatoes into an oiled 1 quart baking dish. Bake 40-45 min, just until the top browns and the casserole is bubbling. Serve with Tabasco sauce.