In a large skillet or sauté pan, melt butter over medium heat. Add the mushrooms, onion, celery and carrots and sauté for 5 minutes. Stir in the chopped chicken and 1/2 teaspoon curry powder; cook, stirring frequently, until the chicken is no longer pink.
Slowly stir in the chicken broth, milk and wine. Sift the flour over the top and whisk to blend. Add remaining 1/2 teaspoon curry powder, edamame and rosemary, whisking until well blended. Bring to a boil, reduce heat and simmer 15 minutes or until thickened. Remove from heat; stir in thyme and oregano and season to taste with salt and pepper. (If using evaporated milk, you may need to add a pinch or two of sugar.) Set aside to cool.
Preheat oven to 375 degrees. Line two large rimmed baking sheets with parchment paper.
Remove 1 sheet of puff pastry from refrigerator. On a lightly floured surface, roll puff pastry into a 12-inch square. Cut into 12 rectangles, 3 x 4 inches each.
Place the 6 squares on a work surface. Place 3 tablespoons of the chicken filling in the middle of each square, leaving a 1/4-inch border. Roll the remaining squares to be slightly larger and place on top of the filling. Gently press around the edges with your finger, then press around the edges with the tines of a small fork to seal. Place on prepared baking sheets.
Repeat with second puff pastry sheet and remaining filling.
In a small mixing bowl, whisk together the egg and water. Brush on top of pastry envelopes. Cut 4 small slits in the top of each envelope to vent. Bake for 20 to 30 minutes, or until puffy and golden brown. Let cool around 10 minutes before serving.
MAKE AHEAD: Pot pie filling can be prepared, cooled, covered and refrigerated up to 24 hours in advance. Envelopes can be prepared and frozen for up to 3 months. Bring to room temperature before baking.
VEGETARIAN VARIATION: In place of the chicken, use 1/4 bunch fresh asparagus, tough ends removed and sliced into 1/4-inch pieces. Follow same directions as above.