Potato Knish Casserole

Potato Knish Casserole (Easy One-Pan Comfort Food)
Love the savory, buttery flavor of a classic potato knish but not up for hours of dough folding? This no-fuss casserole delivers all that nostalgic flavor in a simple, oven-ready dish. Perfect for a cozy dinner or laid-back weekend bite.
đź“‹ Ingredients
Ingredient | Amount |
---|---|
Unsalted butter | ÂĽ cup |
Yellow onions, diced | 2 large |
Yukon Gold potatoes, peeled and quartered | 2½ pounds |
Full-fat sour cream | 1 cup |
Store-bought pie crust, thawed | 1 round |
Large egg | 1 |
Olive oil | 1 tablespoon |
Water | 1–2 teaspoons |
Kosher salt and black pepper | To taste |
🍳 Instructions
1. Preheat and Prepare Pan
Preheat your oven to 350°F (175°C). Lightly grease a 9×9-inch baking dish and set aside.
2. Caramelize the Onions
In a medium pan, melt the butter over medium heat. Add the diced onions and cook until golden and tender, about 10 minutes. Season with salt and pepper, then remove from heat.
3. Cook the Potatoes
Add potatoes to a large pot and cover with water. Stir in 1 tablespoon of kosher salt. Bring to a boil, then simmer for around 10 minutes, or until potatoes are easily pierced with a fork. Drain and place in a large bowl.
4. Mash and Mix
Mash the potatoes until mostly smooth. Stir in sour cream along with salt and pepper to taste. Fold in the caramelized onions until fully incorporated.
5. Assemble the Casserole
Transfer the mashed potato mixture into your prepared baking dish, spreading it evenly. Top with the defrosted pie dough, trimming edges as needed to fit neatly.
6. Prepare Egg Wash
In a small bowl, whisk together the egg, olive oil, and water. Brush this mixture over the pie crust for a golden, glossy finish.
7. Bake to Perfection
Place the dish in the oven and bake for 25–30 minutes, or until the crust is crisp and beautifully golden brown.
8. Serve and Enjoy
Cut into squares while warm and serve on its own or alongside a crisp salad or tangy pickles for the full knish experience.
👩‍🍳 Tips for Extra Flavor
- Craving more depth? Stir in a pinch of ground mustard to the filling.
- Want it creamier? Swap sour cream with whipped cream cheese for a richer texture.