Potato hash with spinach and eggs

Ingredients
3/4 lb small white potatoes, cut into 1/2-inch pieces
coarse salt
1 medium yellow onion, diced small
1 red bell pepper, seeded and diced small
1/2 tsp red-pepper flakes
10 oz frozen chopped spinach, thawed and excess liquid squeezed out
8 eggs
1 oz grated Parmesan, about 1/4 cup
1 tbsp fresh parsley, chopped

Instructions:

In a large cast-iron or other heavy skillet, bring potatoes to a boil in salted water over high. Cook until potatoes are tender when pierced with a knife, about 6 minutes. Drain.

In skillet, melt 2 tablespoons butter over medium. Add onion and bell pepper and cook for 5 minutes. Add potatoes and red-pepper flakes; season with salt. Cook until potatoes are golden, 6-8 minutes. Add spinach and 1 tablespoon butter and cook, stirring, until butter is melted. Make four wells in potato mixture. Crack 2 eggs into each well and reduce heat to medium-low. Cover and cook until whites are set but yolks are still runny, about 6 minutes. Sprinkle with Parmesan and parsley and serve immediately.