Make the dough by adding the flour, butter and salt to a food processor. Pulse a few times, just until the mixture resembles course crumbs. Then, with the machine running, pour the ice water in through the feed tube.
Continue running until the dough comes together. Turn it out onto a floured surface and form into a dough ball. Cut into 4 equal pieces, wrap each in plastic wrap and refrigerate for at least one hour.
Add the lentils and water to a large pot and bring to a boil. Cover, reduce the heat to low and simmer for 10 minutes. Remove from the heat, uncover and allow to cool. Season with the za'atar.
While the lentils are cooking, add the butter and onion to a large pan and saute until translucent. Add the garlic and cook for another minute. Stir in the flour until the onion mixture is thoroughly coated and then stir in the milk.
Add in the grated cheese and continue cooking on medium heat until melted. Stir in the peas and carrots and cook for another few minutes until the mixture begins to thicken. Season with salt and pepper and stir in the parsley.
Add the cooked lentils to the cheese mixture and remove from the heat. Allow to cool for a few minutes while you pre-heat the oven to 375 degrees.
Cut about a third off each dough ball (those will be your pot pie lids) and, on a well floured surface, roll the remainder of each ball out fairly thinly. Drape it over each of the mini spring-form pans and press in.
Add an equal amount of the lentil filling to each pan. Roll out the "lids" and cover each pie. Roll the edges together to seal and cut a slit in the center. Brush with cream and sprinkle on a little sea salt.
Place the spring-form pans on a sheet pan to catch any drips and bake in the oven for approximately 50 minutes or until the tops are a light golden brown.
When cool enough to handle, release the spring form and serve.