You can cook the rhubarb and
pastry rectangles in advance and store them overnight in air - tight containers.
This comforting classic never loses its luster, especially when it's spun into a soup, with chicken thighs, green beans, leek, carrots, celery and parsnip in a thyme - infused chicken broth, served with
puff pastry rectangles.
Using a sharp knife, score a border within
each pastry rectangle about two cm (3/4 inch) from the edge, being careful to avoid cutting right through the pastry.
The warm potato - leek - onion mixture is then tossed in a large mixing bowl with a touch of heavy cream, before being evenly distributed on the puff
pastry rectangles, layered with sharp cheddar cheese, and sealed with another top layer of puff pastry.
Add 1 - 2 tablespoons of filling to the right side of the center of
each pastry rectangle, and using your finger, brush the edges of each rectangle with a little water.
Arrange
the pastry rectangles so they are lengthwise in front of you.
Leaving about 1/2» around the edges, sprinkle the flour mixture across the surface of
the pastry rectangle.
Put the filling you're going to use in a piping bag and pipe a small amount onto half of
the pastry rectangles.