Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper or lightly grease it.

In a large mixing bowl, combine the diced sweet potatoes, olive oil, onion, paprika, cumin, crushed red pepper flakes (if using), and a pinch of salt and pepper. Toss until evenly coated. Spread the sweet potatoes out in a single layer on the baking sheet. Sprinkle in sausage.

Roast in the oven for 25 minutes, stirring halfway through, until the sweet potatoes are tender and the sausage is browned and fully cooked.

Remove the baking sheet from the oven and the spinach over the roasted mixture. Toss gently to combine. (If not using eggs, cook an additional 5 minutes,) If you want to add eggs, create small wells in the hash after adding the spinach. Crack eggs into the wells and return to the oven for 6–8 minutes, or until the egg whites are set but the yolks are still runny.

Serve the roasted hash hot, garnished with fresh parsley, if desired.