Set it aside. In the same pan (low heat), pour 1 tablespoon of oil and 10 gr of cornstarch. Whisk.
To avoid lumps, gradually add chicken stock and immediately stir.
Now add milk, chopped carrots, frozen peas, salt and pepper. Cook for about 8 minutes or until the peas are softer.
Add cooked chicken and turn off the heat. Cover.
Assemble the pie:
Take the pie pan out of the oven, add the filling.
Take another phyllo sheet and brush it with the mixture of extra virgin olive oil and water, then fold it in half and place it on top of the filled pie pan. Cut slits on top, like you'd do with an apple pie.
Brush with extra olive oil and bake for about 20 minutes or until golden brown.