6 ounces pastrami or leftover roast, sliced thick & cut into 1/4” dice
4 tablespoons mild olive oil
2 large leeks, halved lengthwise and soaked
4-5 cloves garlic crushed
1 cup chicken or vegetable stock (soup)
1 teaspoon kosher salt, divided
2 heaping tablespoons mayonnaise (purchased or homemade)
freshly ground black pepper
2 medium sweet potatoes
4 medium Idaho or russet potatoes
prepare the leek filling:
In a medium sized sauté pan, heat the olive oil. Add the meat and sauté, stirring occasionally, until heated through, about 5-6 minutes. While the meat is cooking, drain the leeks and slice them into 1/4” pieces. Set aside. Remove pastrami with a slotted spoon and set aside.
Add the garlic and leeks to the saucepan. Cover and sweat for 5 minutes over a low flame, stirring occasionally. Don’t allow them to brown. Add the broth, and 1/2 teaspoon salt. Bring to a boil and simmer 5 minutes. Add the, pepper and meat. Allow to cool 5 minutes and beat in the eggs and mayonnaise.
prepare the gratin:
Preheat oven to 350 degrees. Peel and slice the potatoes and sweet potatoes, 1/4” thick. Lightly grease a 9”x13” or 2 quart casserole dish. Arrange one overlapping layer of Idaho potatoes in the pan. Season the potatoes with a pinch of salt and pepper. Spread 1/3 of leek filling evenly over the potatoes. Arrange a layer of overlapping sweet potatoes over the leek filling. Season with a pinch of salt and pepper. Spread 1/3 of leek filling over the sweet potatoes. Arrange the last layer of potatoes over the leek filling. Season the potatoes once again with a pinch of salt and pepper. Using your hands, or a large spatula, press down on the potatoes to compact the layers. Spread the remaining leek filling over the top.
Bake 1 hour or until golden and crispy on top. Allow to rest 15 minutes before serving. May be made 2 days in advance and reheated before serving.