Boil the peeled and chopped russet potatoes in a large pot of cold water until fork-tender, about 5–7 minutes. Drain and set aside.

In a nonstick skillet, heat vegetable oil over medium-high heat. Cook the lean ground beef, breaking it apart, for about 5–7 minutes until browned. Drain excess fat and keep warm.

Sauté the diced onion and minced garlic in the same skillet for about 2 minutes until translucent. Add the boiled potatoes, Italian seasoning, salt, and black pepper, cooking for an additional 5 minutes until browned.

Return the cooked ground beef to the skillet and mix thoroughly. Sprinkle the shredded cheddar cheese on top and cover to allow it to melt, about 1 minute.

Serve the hash hot, garnished with fresh herbs or sour cream if desired.