Add the diced sweet potato to a small saucepan full of cold, salted water. Bring to a boil then cook them until they are almost tender, about 6-8 minutes. Drain the sweet potato then lay the pieces out on paper towels to dry.

Heat a large skillet over medium-high heat and swirl with the olive oil to coat the bottom. Add the red onion and diced sweet potato to the skillet and spread it out in a single layer. Cook for 3-5 minutes or until they turn golden brown and crusty.

Flip the potatoes and onions and add in the corned beef and kale. Season with salt and pepper and continue cooking until the kale has wilted and everything is heated through, about 3 minutes. Top the hash with 1-2 fried eggs if desired.