Lamb Pie with Mashed Potatoes and Eggplant

This Greek-inspired shepherd's pie is made with lamb, eggplant, and oregano. The mashed potato topping gets its Greek flavour from kasseri cheese, a hard, salty cheese. If you can't find kasseri cheese, use Pecorino Romano instead. Finish the dish with a sprinkling of chopped fresh oregano, if desired.

Filling:
1 (1½ lb) eggplant, unpeeled, cut into ¾-1" cubes
coarse sea salt
7 Tbsp. extra-virgin olive oil, divided
2 lbs lamb shoulder, boneless, well-trimmed, cut into 1" cubes
all-purpose flour, unbleached
3 cups onions, chopped
1 cup dry white wine
1 (28 oz) can diced tomatoes in juice
3 cups beef broth
8 cloves garlic, chopped
1 Tbsp. dried oregano

Topping:
2½ lbs russet potatoes, peeled, cut into 1" cubes
2 Tbsp. (¼ stick) butter
2 Tbsp. extra-virgin olive oil
2 cloves garlic, minced
¾ cup whole milk
1¼ cups kasseri cheese, packed, coarsely grated (5-6 oz)

For the Filling:
Scatter eggplant on rimmed baking sheet. Sprinkle with coarse salt; let stand 1 hour, tossing occasionally. Rinse eggplant and pat very dry.

Heat 3 Tbsp. oil in heavy large pot over medium-high heat. Add eggplant and sauté until tender, about 12 minutes. Transfer to medium bowl.

Sprinkle lamb generously with coarse salt and pepper, then dust with flour to coat. Heat 2 Tbsp. oil in same pot over medium-high heat. Add half of lamb. Sauté until browned, about 8 minutes. Transfer lamb to large bowl. Repeat with 2 Tbsp. oil and remaining lamb.

Add 1 additional Tbsp. oil to same pot, if needed. Add onions. Cover and cook over medium-low heat until very tender, about 10 minutes (bottom of pot will be very dark). Add wine to pot. Increase heat and boil until wine evaporates, scraping up browned bits, about 5 minutes. Add tomatoes with juice, broth, garlic and oregano; bring to boil.

Add lamb with any accumulated juices. Cover; reduce heat to low and simmer 1 hour. Uncover and continue to simmer until lamb is very tender and gravy thickens slightly, about 45 minutes. Stir in eggplant. Season with salt and pepper. Transfer to 9x13x2" glass baking dish.

Make-Ahead: Can be made 3 days ahead. Cool slightly. Cover and chill.

Preheat an oven to 375°F (190°C/170°C fan, Gas Mark 5).

For the Topping:
Cook potatoes in large pot of boiling salted water until tender, about 14 minutes.

Meanwhile, melt butter with oil in medium saucepan over medium-high heat. Add garlic. Sauté until fragrant, about 1 minute. Add milk and bring to simmer.

Drain potatoes. Return to pot. Stir over medium heat until excess moisture evaporates. Add milk mixture and mash potatoes until just smooth. Stir in cheese. Season with coarse salt and pepper. Drop potatoes over filling by heaping Tbsp., covering completely.

Bake pie until filling is heated through and topping is golden, about 45 minutes.

Makes 8-10 servings.