Pittsburgh Pierogi Casserole

Ingredients

• 12 lasagna noodles
• 3 lb russet potatoes, peeled and cubed
• 2 sticks unsalted butter
• 3 large yellow onions, sliced thin
• 2 cups shredded sharp cheddar cheese
• 4 oz cream cheese, softened
• 3/4 cup sour cream
• 1/2 cup whole milk, warmed
• 2 tsp kosher salt
• 1 tsp black pepper
• 1/2 tsp garlic powder
• 3 tbsp chopped fresh chives

Before you cook

• Peel the potatoes and cut them into 1-inch cubes.
• Slice the onions as thin as you can.
• Let the cream cheese sit out until soft.
• Warm the milk.
• Butter a 9-by-13-inch baking dish.

Steps

1. Put the potatoes in a large pot, cover them with cold salted water, and boil them for 15 minutes, until completely tender.
2. Drain the potatoes and return them to the dry pot for a minute to steam off.
3. Mash the potatoes with the cream cheese, sour cream, and warm milk until smooth.
4. Stir in 1 1/2 cups of the cheddar, the salt, pepper, and garlic powder.
5. Melt one stick of the butter in a large skillet over medium heat.
6. Add the sliced onions and cook them for 25 minutes, stirring every few minutes, until they are deep golden and jammy.
7. Heat the oven to 350 degrees Fahrenheit.
8. Bring a large pot of salted water to a boil and cook the lasagna noodles until just pliable, about 8 minutes.
9. Drain the noodles and lay them flat on a towel so they do not stick together.
10. Melt the second stick of butter in a small pan.
11. Brush a little melted butter across the bottom of the buttered baking dish.
12. Lay down four lasagna noodles in a single overlapping layer.
13. Spread half the mashed potato mixture over the noodles.
14. Scatter a third of the caramelized onions over the potatoes.
15. Add another four noodles, the rest of the potatoes, and another third of the onions.
16. Lay the last four noodles on top and brush them generously with the remaining melted butter.
17. Scatter the last of the onions and the remaining 1/2 cup cheddar over the top.
18. Cover the dish with foil and bake for 25 minutes.
19. Remove the foil and bake for 15 minutes more, until the top noodles crisp at the edges.
20. Rest the casserole for 10 minutes, then scatter the chives over the top.