Ingredients
Equipment
Method
- Place peeled and cubed potatoes in a large pot of cold, salted water. Bring to a gentle boil and cook until fork-tender. Drain and let sit in a colander for two minutes to allow excess steam to escape.
- While the potatoes are cooking, heat oil in a large cast-iron skillet over medium heat. Sauté the finely diced onions and carrots until the onions are translucent and carrots have softened.
- Push the vegetables to the edge of the skillet and add the ground lamb to the center. Brown the meat in small batches, breaking it into crumbles, until a dark savory crust forms. Drain excess fat if necessary.
- Stir in the tomato paste and cook for 60 seconds until it reaches a dark brick red color.
- Pour in the Guinness Draught, scraping the bottom of the pan to deglaze and release the flavorful brown bits. Simmer until the liquid has reduced by half to concentrate the flavor.
- Add the stock, Worcestershire sauce, rosemary, and thyme. Bring to a simmer and cook for 15 minutes until the sauce thickens into a rich, glossy gravy. Stir in frozen peas if desired.
- Mash the potatoes using a ricer for the best texture. Stir in the butter, heavy cream, and egg yolk. Season generously with salt and white pepper.
- Spread the lamb filling into a baking dish (or leave in the oven-safe skillet). Spoon the mashed potatoes over the top, using a fork to create ridges and peaks across the surface.
- Bake in a preheated oven at 400°F (200°C) for approximately 20 minutes until the filling is bubbling and the potato peaks are toasted gold. Broil for the final 2 minutes if extra browning is desired.
Notes
The secret to this dish is the Maillard reaction; ensure the meat is well-browned for a savory foundation. Using a ricer for the potatoes prevents them from becoming gluey. For a variation, try adding a layer of sharp Irish cheddar between the meat and potatoes to create a cheese barrier. If substituting lamb with beef, the dish becomes a 'Cottage Pie'.