White pizza with ham and rocket (for 4 persons)

ingredients: 
500 grams (1.1 Lbs) of flour
25 grams (1 oz) of brewer's yeast
5 tablespoons of extra virgin olive oil
200 grams (9 oz) leaves of hamRocket
Salt and pepper

preparation:Put the flour in a large bowl, dissolve the yeast in a large glass of warm water and add it to the flour, along with the oil and a pinch of salt. Mix well then knead with your hands, adding a little water or flour if necessary, until the dough become smooth and elastic.
Dust a large container with flour and add the dough in the shape of a ball with a cross-shaped cut on the top to help it rise. Cover with a tea cloth and leave in a warm place for about two hours. The dough is ready when it has doubled its volume.
Take the dough and divide it into four equal parts. Roll out each part with a rolling-pin until you have a disc about 30 cm. in diameter.
Add a drizzle of extra virgin olive oil, salt and pepper and place in preheated oven at 250°C (490°F) for about 10-15 and or until the pasta is sufficiently cooked.
Remove from the oven and cover with rocket leaves, add a drizzle of extra virgin olive oil and the slices of ham to serve.