In a deep bowl, mix the flour and flaxseed, then add the oil and yogurt and mix well. You should get a mixture that will not stick. If it is very dry you can add a little yogurt or if it is very wet you can add a little more flour.
When you make a nice ball as in the picture, make a thin crust out of it and make circles with the help of a cup or a small plate. You can leave it big, if that makes it easier for you.
Coat each circle with butter, then arrange the spinach on each pizza and finally add a little grated cheese.
Bake in a preheated oven at 350 degrees F for about 10-12 minutes. They are ready quickly, if your oven is strong, make sure they do not burn.These mini pizzas are perfectly combined with fresh tomatoes on top! Enjoy!