Prepare the chicken. Either bake it on a sheet in the oven at 450℉ for 15-20 minutes or place the chicken breast in a slow cooker with a splash of water (and some salt and pepper) and cook for four hours on high. Then remove it and shred the chicken with two forks.
1 large chicken breast
Preheat the oven to 375℉. In your Dutch oven, add the butter and let it melt over medium heat. Add the onion and a pinch of salt of pepper. Cook until they begin to turn translucent.
3 tbsp unsalted butter, ½ yellow onion, salt and pepper
Add in the garlic, carrot, celery and potatoes. Cook until the vegetables begin to soften, about 3-5 minutes. Then add the white wine and continue cooking on medium until it reduces by half.
4 cloves garlic, 3 celery stalks, 3 long carrots, 1 yellow potato, ½ cup dry white wine
Add the flour and stir until everything is well coated. Let the mixture cook for 1 minute - it will start to turn golden. Then add your milk and mix thoroughly.
¼ cup all purpose flour, 2 cups almond milk
Pour in the chicken broth, water, Dijon mustard, bay leaf, parsley, and grated Parmesan. Mix together. Then reduce the heat to a simmer and allow it to thicken for 15 minutes.
1 cup chicken broth, 1½ cups water, 1 bay leaf, ¼ cup fresh parsley, 1 tbsp Dijon mustard, ¼ cup parmesan cheese
Before baking, make the phyllo topping. Take a sheet of phyllo dough and brush it thoroughly with butter. Then gently crumple the sides of the phyllo sheet together and gently place it on top of the pot pie, starting in one corner. Repeat the process until the whole top is filled. Sprinkle it with sea salt and dab remaining butter on the surface of the sheets.
10 sheets phyllo dough, 4 tbsp unsalted butter, flaky sea salt
Place the pot pie in the oven to bake (uncovered) for about 20 minutes, or until the top is a nice golden brown. Sprinkle on the thyme and serve.
2 tbsp fresh thyme leaves