Tip the flour into a large bowl and make a well in the centre. Add the yeast and salt, then gradually pour in 350ml tepid water, stirring as you go. Bring the dough together with a spoon, then with your hands. It should be soft, but not too sticky or wet. If it won’t come together, pour in a little extra water; if the dough is too wet, add extra flour. Tip onto a floured work surface and knead for about 10 mins, or until it’s smooth, soft and springs back when pushed with a finger. Leave to rise in an oiled bowl covered with cling film in a warm place for 1 hr or Packed with summer flavours until the dough has doubled in size.
Strip leaves from half the rosemary and finely chop. Break the rest into smaller pieces. Drain the artichokes, reserving the oil, and chop into chunks.
When risen, tip the dough onto an oiled work surface and roll out into a 35 x 45cm rectangle. Slip an oiled baking sheet under half of the dough. Top the half with artichokes, all the Parmesan and rosemary. Grind over black pepper and drizzle with a little of the reserved oil. Fold over the other dough half, pressing the edges together and under to seal. Leave to rise in a warm place, covered with the oiled cling film, for 30 mins. Heat oven to 240C/fan 220C/gas 9.
Drizzle with a little more of the oil and make dents in the top with your fingers. Pop the rosemary sprigs into the dents and grate over a little more cheese. Bake for 15 mins, until golden and risen. Cool on a rack for 30 mins, cut into squares and serve.