Ingredients:

  • 3 tablespoons olive oil (45 ml)
  • 1 large onion, chopped (about 1 ½ cups)
  • 2 carrots, peeled and chopped (about 1 cup)
  • 2 celery stalks, chopped (about ¾ cup)
  • 2 cloves garlic, minced
  • 1 ½ pounds cooked corned beef, cubed (680 grams)
  • 1 cup beef broth (240 ml)
  • 1 cup dark beer (such as Guinness or stout) (240 ml)
  • 1 tablespoon tomato paste
  • 1 teaspoon dried thyme
  • ½ teaspoon black pepper
  • 1 bay leaf
  • 1 cup frozen peas (110 grams)
  • 1/2 cup frozen corn (55 grams)
  • 3 pounds Yukon Gold potatoes, peeled and quartered (1.36 kg)
  • ½ cup whole milk, warmed (120 ml)
  • 4 tablespoons unsalted butter, softened (57 grams)
  • Salt and freshly ground black pepper to taste

Instructions:

  1. Heat olive oil in the Dutch oven, and sauté onion, carrots, and celery until softened. Add garlic and cook briefly.
  2. Stir in cubed corned beef, beef broth, beer, tomato paste, thyme, pepper, and bay leaf. Bring to a simmer, reduce heat, cover, and cook for at least 2 hours, or until the corned beef is very tender.
  3. While the filling simmers, boil potatoes in salted water until tender.
  4. Drain the potatoes and return them to the saucepan. Mash them well. Add warm milk and butter, and continue mashing until smooth and creamy. Season with salt and pepper to taste.
  5. Remove the bay leaf from the corned beef filling. Stir in frozen peas and corn. Transfer the filling to the baking dish.
  6. Spread the mashed potatoes evenly over the corned beef filling.
  7. Bake in a preheated oven at 375°F (190°C) for 20-25 minutes, or until the potato topping is golden brown and the filling is bubbly.
  8. Let cool for 10 minutes before serving.