|3||pounds (4 to 5) russet (baking) potatoes, peeled, cut into 1/2-inch pieces|
|3||tablespoons vegetable oil|
|8||ounces portobello mushrooms, chopped|
|2/3||cooked brisket, coarsely chopped|
|6||cups cooked brisket vegetables|
|1 1/2||cups brisket cooking juices, or more|
|Salt and pepper, to taste|
1. Set the oven at 400 degrees. Have on hand a 9-by-13-inch baking dish.
2. In a large pot fitted with a steamer basket, bring about 1 inch of water to a boil. Place the potatoes in the basket, cover, and steam for 12 to 15 minutes or until the potatoes are tender when pierced with a skewer. Drain into a colander.
3. In a skillet over medium-high heat, heat 1 tablespoon of the oil. Cook the mushrooms, stirring often, for 5 minutes or until they release their liquid and it evaporates.
4. In the baking dish, layer the brisket, vegetables, mushrooms, and juices. Cover with potatoes. Sprinkle the potatoes with salt, pepper, and the remaining 2 tablespoons oil.
5. Bake the casserole for 30 minutes or until bubbling at the sides.
6. Turn on the broiler. Broil the casserole, watching it carefully, for 8 to 10 minutes or until the potatoes are golden.