Pierogi

Bahan-bahan (30 porsi)

• 4 cups all-purpose flour
• 2 teaspoons salt
• ½ cup vegetable oil
• 2 large eggs
• ¾ cup warm water
• 2 medium russet potatoes
• 2 tablespoons unsalted butter
• ¼ cup cottage cheese (or sour cream)
• 1 cup shredded cheddar cheese
• 1 teaspoon salt
• 1 small sweet onion
• 3 tablespoons unsalted butter