In a medium pot, boil water and add 1 teaspoon salt, add potatoes and cook until almost fork tender. When cooked, strain potatoes, and pat dry with paper towels.
Meanwhile in a large saute pan, add 2 tablespoons olive oil, and 1 tablespoon butter, add red onions, peppers and corned beef. Saute until onions are translucent, then add garlic, season with salt, pepper, and paprika. Cook for 2 minutes, remove from pan and hold hot.
In the same pan, add 3 tablespoons olive oil, and the potatoes. Cook until crispy on all sides. When cooked and crispy, add the pepper, onion and corned beef mixture. Combine thoroughly, being careful to not break the potatoes.
Pour mixture into a serving bowl, top with Cheddar, avocado slices, sour cream and green onions.