Tip the flour into a large bowl and stir in the salt, sugar and yeast. Pour in the water and mix with your hand, then bring the dough together.
Turn the dough out onto a lightly floured surface and knead vigorously for 10 minutes. Transfer to a large lightly oiled bowl and cover with a clean cloth. Stand in a warm place and leave to rise until doubled in size – about 1 hour.
Knead the dough lightly for 1 minute, then roll it out on a lightly floured surface into a rectangle measuring approximately 50x30cm.
Spread the red pesto or sun-dried tomato paste over the dough, leaving a 2cm border along one long edge. Scatter the rosemary and Parmigiano Reggiano evenly over the surface.
From the other long edge, roll the rectangle into a sausage-shape, pressing the long edge to seal it. Curl the roll around into a circle, sealing the ends together.
Lift the ring onto a large greased baking sheet, then cut 16 even slices with a sharp knife, without cutting right through, keeping the circular shape.
Twist each slice so that the cut surface lies upwards. Sprinkle with poppy seeds or sesame seeds. Leave in a warm place for 30-40 minutes to rise.
Meanwhile, preheat the oven to 210°C/Fan 190°C/Gas Mark 7. Bake the garland for 20-25 minutes until risen and golden brown. Cool on a wire rack.
Scatter the garland with shavings of Parmigiano Reggiano and sprigs of rosemary and serve with olives, artichokes and sun-dried tomatoes in olive oil.
Cook’s tip: To make separate buns, cut through each slice completely and arrange on lightly greased baking sheets, cut side up, leaving them to rise as before.