Down-Home Vegetable Pot Pie

Ingredients

• celery

  finely chopped ( 2/3 cup)
  1 stalk
• Tbs. vegetable oil
  1 unit
• all-purpose flour
  1/4 cup
• vegetable broth
  1 1/2 cups
• milk
  1 cup
• dried thyme
  1/2 tsp
• Onion

  finely chopped (1 1/2 cups)
  1 large
• Pastry topping
  1 unit
• unbleached all-purpose flour
  1 2/3 cups
• Tbs. Sugar
  1 unit
• salt
  1/2 tsp
• baking powder
  1/2 tsp
• stick (8 Tbs.) cold unsalted butter

  cut into small pieces
  1 unit
• Tbs. ice-cold water
  4 1/2 unit
• all-purpose potatoes

  peeled and cut in 1/2-inch dice (2 1/3 cups)
  2 medium
• carrots

  peeled and cut into 1/2-inch dice (1 cup)
  2 large
• frozen corn
  1 1/2 cups
• frozen Peas
  1 1/2 cups
• Tbs. unsalted butter
  1 1/2 unit