In a bowl, knead a dough from the flour, egg, milk, yoghurt, yeast, olive oil and baking soda.
Leave the dough in a warm area to rise.
Divide it up into equal-sized balls, roll them out into thin sheets like pizza crusts.
Lay out the rolled out sheets onto a tray covered with baking paper.
Arrange the sausages on top, cover with grated cheese.
Clean the mushrooms, chop them thinly and also arrange on top of the pizzas.
Bake at 392°F (200 °C) for 20 min.