Foryoueats: Pierogi

Ingredients

• For the Dough:
• 4 cups all-purpose flour, spooned into measuring cup and leveled-off, plus more for kneading and rolling
• 1 teaspoon salt
• 1 cup room temperature water
• 2 large eggs
• For the Filling:
• 3 tablespoons unsalted butter
• 3 medium yellow onions (1½ pounds), finely diced
• Salt and freshly ground black pepper
• 1 cup mashed waxy potatoes, from 1 lb of yellow potatoes (see note)
• 1 cup cottage cheese
• For Sautéing and Serving:
• Vegetable oil (to prevent sticking)
• Unsalted butter
• Fresh parsley or dill
• Sour cream