Chicken and Tarragon Pies

I found this recipe in the magazine called Food Idea. We had this for tonight and was really good. I never tasted tarragon before and wanted to try. When I was making this, I tasted little bit and I wasn't quite sure whether I will like it or not, but it came out really well. So I wanted share this with you for cold night.

• Ready In: 55 mins
• Serves: 4

Ingredients

• 1  bunch  bulb spring onion (I used normal brown onion)
• 1  tablespoon margarine
• 250  g button mushrooms, sliced
• 750  g chicken breast fillets, trimmed chopped into 3cm pieces
• 1  cup  chicken stock
• 1⁄4 cup tarragon leaf, roughly chopped (I used dried tarragon leaves about 1/2 table spoons, I think)
• 2  tablespoons cornflour
• 4  sheets  frozen premade puff pastry, partially thawed
•  olive oil flavored cooking spray

Directions

1. preheat oven to 200°C Grease four 13/4-cup capacity ramekins or pudding basins.
2. Trim and quarter onions, leaving 1cm of green stalk at top.
3. Melt margarine in a large, deep frying pan over medium heat. Add onion and cook for 3 minutes or until juice evaporates. Add chicken and cook for 5 minutes or until golden browned.
4. Add stock and tarragon. Bring to the boil. Reduce heat and simmer for 3 minutes. Combine cornflour and 2 tablespoons water. Pour into pan in a steady stream, stirring constantly to prevent lumps from forming. Simmer for 2 minutes or until thick. Season with salt and pepper. Set aside to cool completely.
5. Using the top of dish, cut a disc 2cm wider than the dish (all the way round) from each sheet. Spoon filling into ramekins. Top with pastry rounds, pressing edges to seal. Spray with oil. Sprinkle with salt and pepper. Cut a small cross in pie tops.
6. Bake for 30 to 35 minutes or until pastry is light golden and puffed.