4–5 boiling potatoes (2 pounds), such as yukon golds or red-skinned new potatoes, scrubbed or peeled, cut in half, crosswise.
4 tablespoons olive oil, divided
1 large yellow Onion, diced (1 1/2 cups)
2 carrots, peeled, sliced in half lengthwise, thinly sliced crosswise
1 medium zucchini, sliced in quarters lengthwise, thinly sliced crosswise
1 green or yellow pepper, seeded and diced
10 ounces cooked corned beef or cooked bacon or ham, cubed or shredded
1/4 teaspoon dried thyme
Salt and pepper to taste
4–5 fresh eggs, if you’re serving the hash with eggs on top
Preheat oven to 225ºF. Bring a large pot of salted water to a boil. Add potatoes. Cook for 20-25 minutes, until potatoes are just cooked through. Drain potatoes in a colander. Let them cool. Cut them into 1/2-inch dice, set aside.
Heat 2 tablespoons oil in a large cast iron skillet over medium heat. (You can also use a non-stick skillet, but keep a close eye on the heat to ensure the veggies and potatoes don’t burn) Add onions, peppers, zucchini and carrots. Push them down into the pan in a single layer and leave them undisturbed for 3 minutes to brown. Flip them and leave them for another 2-3 minutes. Add corned beef and cook, tossing everything in the skillet for another minute or two. Sprinkle with thyme and a few grinds of black pepper. Transfer the mixture to a casserole or heatproof bowl and set aside.
Add 2 tablespoons oil to the skillet. Add potatoes. Press potatoes down into the pan into a single layer. Cook, undisturbed, for 7-8 minutes, until a golden crust is formed on the bottom. Sprinkle potatoes with 1/2 teaspoon salt and several grinds of black pepper and toss. Transfer potatoes to the casserole or bowl with rest of the mix. Put it in the oven to keep warm until you’re ready to serve.
Poach eggs, if using. Divide hash among 4-5 plates and serve with poached eggs on top, if you like. Pass around extra salt and pepper.