Knish from New York Cult Recipes by Marc Grossman

Ingredients

• 3 teaspoons matzo meal or ordinary breadcrumbs
• 1½ tablespoons cooking oil
• 1 brown onion, finely chopped
• 320 g (11¼ oz) potatoes, cut into cubes
• 1½ tablespoons sunflower oil
• 1 teaspoon baking powder
• 190 g (6¾ oz) plain (all purpose) flour
• 1 egg, beaten (set 2 teaspoons aside for glazing)
• 2 pinches salt
• 45 ml (1½ fl oz) water
• 1 egg
• 3 pinches sugar