Potato, Pastrami, and Gruyere Knishes | America's Test Kitchen

Ingredients

• 2 1/4 pounds (1021 grams) russet potatoes , peeled and cut into 1-inch pieces
• 1 teaspoon table salt , divided plus extra for boiling
• 1/2 teaspoon black pepper
• 4 ounces (113 grams) Gruyère cheese , shredded (1 cup)
• 4 ounces (113 grams) sliced deli pastrami , chopped
• 2 tablespoons yellow mustard
• 1 teaspoon crushed caraway seeds
• 1/2 teaspoon dried dill
• 1 tablespoon olive oil
• 3 onions , chopped fine
• 2 cups all-purpose flour
• 1 1/2 teaspoons baking powder
• 3/4 cup olive oil
• 1/2 cup water
• 2 large eggs , 1 egg beaten with 1 tablespoon water
• 1 teaspoon salt