Combine all the ingredients in a large mixing bowl and knead for a few minutes by hand (or with the kitchen aid). Add some more water if the dough is too dry. Leave to rest for 15 min (meanwhile you can prepare the filling).
Sprinkle some flour on the worktop and roll out the dough using a rolling pin.
Put the dough on baking paper and place it into a low round pie mould with a diameter of ca. 25 cm (If you use baking paper, you don’t need to grease the pie mould.)
Heat the olive oil in a large cooking pot on medium heat.
Put chopped onion and garlic into the cooking pot and fry lightly.
Add cubes of carrot and stew for 5 min, while stirring occasionally.
Add cubes of peppers and stew for another 5 min, while stirring occasionally.
Add cubes of zucchini, stir well and remove the cooking pot from the heat. Season with the tarragon, pepper and salt. Let the veggies cool for a minute.
Meanwhile, combine cheese, eggs and milk. Season with pepper and salt. Put the mixture into the pot with the veggies and stir well.
Pour the mixture in the pie mould and cover with the almond flakes.
Bake the pie in the oven at 180 °C (350 °F) for 45-50 min.
The pie can be eaten hot or cold, depending on what you like. Great sidedishes are sauteed broccoli with spring onion and sesame seeds, a tomato salad and/or wild rice.