- 1 1/2pounds Yukon Gold potatoes (about 4), peeled and cut into 2-inch pieces
- kosher salt and black pepper
- 1/2cup whole milk
- 2tablespoons unsalted butter
- 1tablespoon olive oil
- 1pound ground beef
- 1/3cup ketchup
- 1tablespoon Worcestershire sauce
- 1 1/2cups frozen peas and carrots
- Heat oven to 425° F. Place the potatoes in a large pot and add cold water to cover.
- Bring to a boil and add 1 teaspoon salt. Reduce heat and simmer until just tender, about 15 minutes. Drain the potatoes and return them to the pot.
- Add the milk, butter, and ¼ teaspoon each salt and pepper to the potatoes and mash.
- Meanwhile, heat the oil in a large skillet over medium-high heat. Add the beef and cook, breaking it up with a spoon, until browned, 5 to 6 minutes.
- Stir in the ketchup, Worcestershire sauce, ½ teaspoon salt, and ¼ teaspoon pepper. Add the peas and carrots.
- Transfer the beef mixture to 4 individual baking dishes and top with the mashed potatoes. Bake until golden brown, 15 to 20 minutes.