Chicken, leek & bacon pie filling – thickening with flour

Watching tv has never been a big hobby of mine. Nowadays I practically never watch live tv (except for events like the Olympics), I only watch pre-recorded or on demand shows. My favorite show in the last few years has been the Australian version of MasterChef. I also tried the American, Canadian, English and Dutch version, but they just don’t suit me, I’m a big fan of the Australian version. It has taught me a lot about food and cooking actually, since watching the show I’ve become a lot more familiar with a lot of ingredients and techniques (I can’t fillet a fish (yet), but at least I have a far better understanding and more respect for the technique).

One of the things that always returns on the show, are delicious pies. Who doesn’t like a warm, hearty pie in the winter (or summer, autumn or spring)? Preferably a pie with a crunchy crusty and nicely set, not too liquid filling. There are several tricks to help you make that perfect pie filling. In pie recipes you will often see that flour is not only used to make the crust, it’s also commonly used in the filling.

My current favorite pie filling using this technique is a wonderful chicken, leek, bacon filling; slightly modified from MasterChef Australia. Apart from sharing my recipe with you, I’ll be explaining why exactly you would add flour to a filling. This post will help you understand the role of flour in order to optimize your own pie fillings.

Chicken, leek, bacon pie filling
  • 200g deboned chicken thighs (you can use chicken breast, but thighs contain more fat and don't get dry as fast)
  • a thin leek
  • 100g bacon
  • thyme
  • 50g flour
  • water or chicken stock
  1. Cook leek with some oil and butter in a frying pan
  2. Add the chicken and bacon and keep on cooking so you get a nice brown colour, some nice caramelization.
  3. Add thyme, sprinkle freely, it gives a great flavour
  4. Mix in flour, you should mix it in before water is added to prevent clumps from forming. By mixing in the flour first you make sure that it absorbs moisture and you can get some extra browning.
  5. Then add water, once you added it, the flour will absorb this water. This is again the gelatinization of strach, it swells up and thickens the mixture. Add enough water so it won't run dry and don't add too much to prevent is from becoming soupy.

This pie filling recipe is actually a pretty easy one, probably even easier than my beef pie filling. You just cook your leek and chicken, fry your bacon (try to get some caramelization) and voila, your flavours are there. It should only take you 20-30 minutes to make the entire thing (without oven time).

Chicken, leek and bacon pie
My chicken, leek and bacon pie at the front, my beef pie in the back.

Thickening properties of flour

Flour is one of my favorite ingredients to discuss, as it’s a vital ingredient is so many varying dishes. One of its roles is the use as a thickening agent. As you can read in my infographic on wheat flour, heating a mixture of water and flour will get it to thicken. So what happens?

Let’s greatly simplify wheat flour, we’ll find that the two most important structural components are gluten and starch. Starch is the one at play here. It consists of two types of molecules: amylose and amylopectin. Both are polsaccharides, made up of long chains of glucose. Amylose is the simple structure, it’s a long linear chain, whereas amylopectin isn’t linear, instead the chain has a lot of branches. Together they intertwine and are distributed through wheat in the form of granules.

When heating flour in water, these starch granules absorb water and swell up. Part of these granules of starch will burst, causing amylose molecules to leak out. That way the starch leaks through the entire mix, bind water and intertangle with one another resulting in a thicker texture.

Heat is essential, but not too much

Heat is essential to initiate the thickening process. If flour hasn’t been whisked in through properly, the heat will cause the outside of these lumps to swell. That prevents water from entering the rest of the clump, making it virtually impossible to get rid of these clumps. This is also why you’ll always be asked to whisk in the flour before the heating process starts, or before the water is added.

Once the mixture has thickened, you shouldn’t continue cooking it for too long. Excessive heating will cause the starches to break down. The thickening can actually be decreased again over time.


So, let those creative juices flowing and use this new piece of science to improve your cooking!

Chicken, leek and bacon pie

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