Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Peel and cube the sweet potato into half-inch pieces, then toss with olive oil and ground turmeric.
Spread the potatoes on the sheet and roast for 20-25 minutes until tender and golden brown.
While potatoes roast, place eggs in a pot of water, bring to a boil, then cover and let sit for 10 minutes before cooling in an ice bath.
Cook the liquid egg whites in a small non-stick skillet over medium heat until fully set, then chop into small pieces.
Peel and chop the hard-boiled eggs into bite-sized chunks.
In a large bowl, whisk together the Greek yogurt, Dijon mustard, lemon juice, sea salt, and black pepper.
Fold the roasted sweet potatoes, chopped eggs, and cooked egg whites into the dressing until well coated.
Divide the baby spinach between plates and top with the golden sweet potato and egg mixture.