Dice the Yukon gold potatoes into small, uniform half-inch cubes to ensure they crisp up perfectly in the pan.
Heat the olive oil in a large cast-iron or non-stick skillet over medium-high heat until shimmering.
Add the diced potatoes to the skillet and cook undisturbed for 5 minutes, then toss and cook for another 5 minutes until golden brown.
Push the potatoes to the outer edges of the pan and add the ground turkey to the center, breaking it apart with a wooden spoon.
Sprinkle the sea salt, black pepper, garlic powder, and smoked paprika over the turkey and potatoes.
Add the diced red bell pepper and yellow onion to the skillet, sautéing everything together until the turkey is cooked through and vegetables are tender.
Lower the heat to medium and pour in the egg whites, folding them into the mixture until they are just opaque and set.
Stir in the baby spinach and remove from heat immediately, allowing the leaves to wilt slightly before serving hot.