- 4 pounds red skinned potatoes, cut into 1-inch cubes
- 1 cup whole milk
- 8 tablespoons unsalted butter
- 16 ounces frozen chopped spinach, (or 4 cups chopped fresh spinach)
- 3/4 cup grated Parmesan cheese
- Kosher salt and pepper, to taste
- 1 cup crispy fried onions
- Preheat oven to 375° F and grease a 9×13” baking pan.
- Add potatoes to a large stockpot or saucepan and cover with water. Bring water to a boil and boil potatoes until they are fork tender.
- Drain potatoes and add back to pot.
- Pour in milk and butter. Mash until smooth.
- Stir in spinach, Parmesan cheese, kosher salt and pepper. Stir until well combined and the spinach is no longer frozen or in chunks.
- Pour into prepared baking dish and cover with crispy fried onions.
- Bake for 20 minutes until top is golden brown and potatoes are hot.