Chicken and Mushroom Pie with Duchess Potato Topping

Step 1: Melt one quarter of the butter in a large, 30 cm nonstick pan over high heat. Add the mushrooms and toss for 3 to 4 minutes, until browned on the surface. Add another quarter of the butter, melt it and toss to coat. Add 1/4 teaspoon each of the salt and black pepper, plus half the garlic. Toss for 30 seconds, until the garlic is golden; the mushrooms will still be firm and will finish cooking later. Transfer to a bowl, scraping out all the garlic bits.

Step 2: Sprinkle the chicken with 1/2 teaspoon salt and 1/4 teaspoon pepper. In the same pan, melt another quarter of the butter until hot and foamy. Sear the chicken for 2 minutes on each side, until golden but still raw inside; cook in batches if needed. Remove to a plate. Once cool enough to handle, cut into 2.5 cm pieces.

Step 3: In the same pan, add the bacon and stir for 15 seconds. Add the onion and cook for 2 minutes, until the edges are golden and beginning to soften. Stir in the remaining garlic and cook for 20 seconds.

Step 4: Add the stout and let it simmer rapidly, scraping the bottom of the pan to loosen the browned bits. Reduce the stout by about 75%.

Step 5: Lower the heat to medium and add the remaining butter. Once melted, sprinkle the flour across the pan and stir for 1 minute. While stirring, pour in half the stock and keep stirring until the flour mixture dissolves. Add the remaining stock, water, tomato paste, 1/4 teaspoon salt and 1/2 teaspoon pepper; stir well.

Step 6: Add the mushrooms and any juices from the bowl. Simmer for 10 minutes, or until the liquid reduces to a fairly thick gravy and the mushrooms are soft. Prepare the mashed potatoes while the filling simmers.

Step 7: Add the chicken and any accumulated juices. Simmer for another 2 to 3 minutes, until the gravy is quite thick and a path drawn across the pan briefly holds its shape. Taste and add more salt if needed.

Step 8: Pour the filling into a 1.5 to 2 L baking pan and smooth the surface.

Step 9: Preheat the oven to 200°C (390°F), or 180°C fan-forced.

Step 10: Pipe mounds of mashed potato over the filling, making swirls with bases about 4.5 cm wide and about 4 cm tall. Fill the gaps with small swirls or blobs, using all the mash. Drizzle with melted butter and sprinkle with Parmesan.

Step 11: Bake for 30 minutes, rotating the pan at the 20-minute mark.

Step 12: Rest for 10 minutes. Sprinkle with parsley if using.

Step 13: Put the potatoes in a large pot of cold tap water. Bring to a boil over high heat and cook for 15 minutes, until soft. Drain, then pass through a potato ricer or mash well with a potato masher in the empty pot. Add the butter, hot milk, 1/2 teaspoon salt and white pepper; stir until creamy but not loose, so the mash holds its shape when piped.

Step 14: Transfer the mash to a piping bag fitted with a star tip.

Tip: For alternatives to a piping bag, see the make-ahead and storage notes.