Potato-filled Samosas

Ingredients

• about 1¼ lbs baking potatoes

  such as Idaho or russet
  1 unit
• (about 9 oz) all-purpose flour

  plus a little more as needed
  2 cups
• salt
  1 tsp
• (1 stick) butter
  8 tbsp
• plain yogurt

  sour cream, or buttermilk
  2 tbsp
• ice water

  plus more as necessary
  1 tbsp
• chopped onion
  1 cup
• fresh chile

  minced, or cayenne to taste
  1 unit
• minced garlic
  1 tbsp
• peeled and minced or grated fresh ginger
  2 tsp
• all-purpose curry powder

  or store-bought curry powder
  1 tbsp
• salt and freshly ground black pepper to taste
  1 unit
• green peas (frozen are fine; defrost them in water to cover while you prepare the other ingredients)
  ½ cup
• vegetable oil for deep-frying
  1 unit