Mix the yeast, sugar and water in a jug and leave to rest until foamy (approximately 10 minutes).
To work by hand: Sift the semolina, bicarbonate of soda and salt onto a clean work surface and make a well in the middle. Pour the yeast liquid and lemon juice into the well. Using a fork, mix the liquid, gradually bringing in the flour from the sides. Continue to mix with a fork until just combined. Use your hands to bring the dough together, then turn onto a clean, lightly floured work surface. Add the olive oil and knead the dough until smooth and elastic. It should come away cleanly from the work surface and takes approximately 10 minutes.
If using a mixer: Combine all ingredients for the Schiacciata dough into a mixer. Mix on the second speed until the dough is smooth and elastic (approximately 5 minutes). It should pull away from the sides of the bowl.
Preheat the oven to 230°C conventional oven/ 210°C fan-forced (450° Fahrenheit/Gas 8). Adjust metal racks to the lowest groove of the oven. Line 2 large shallow baking trays with non-stick baking paper and grease generously with sesame oil.
Lightly dust the inside of a large, clean bowl with flour (large enough to hold dough that is double in size). Place the dough inside the bowl and rub extra virgin olive oil on top. Cover with a damp tea towel and leave to rest in a warm place for 2 hours or until the dough has doubled in size.
Cook the broccoli in a large pot of boiling, salted water over medium heat until very tender (approximately 20-25 minutes). Take the pot off the heat and drain the broccoli well.
To make the filling, heat the olive oil in a large non-stick frying pan over medium heat. Add the garlic and cook without browning for 1-2 minutes. Break up the sausage meat with your hands and add to the frying pan. Cook until the sausage is cooked through. Stir the broccoli, capers and basil into the sausage mixture. Season with salt and pepper to taste, then set aside to cool for 15 minutes.
Remove the dough from the bowl and punch with your fist to push the air out. Knead gently on a lightly floured surface. Divide the dough into 2, leaving the unused portion covered by the damp tea towel. Use a rolling pin to roll each piece of dough into a rectangle shape that is 5mm thick.
Arrange half of the broccoli filling over half of one rectangle, leaving a 1cm border around the edge. Dot tablespoons of half of the Italian passata (or Italian canned chopped tomatoes) over the broccoli filling. Sprinkle half of the Caciocavallo and Parmigiano Reggiano cheese over the broccoli filling and add a drizzle of extra virgin olive oil. Brush the outer edge with water, then fold the dough over to enclose the filling. Press edges together to seal, then crimp edges. Gently transfer the Schiacciata to the greased baking tray. Use a fork to prick the top of the Schiacciata and brush with olive oil. Repeat with the remaining portion of Schiacciata dough.
Reduce oven temperature to 200°C conventional oven/ 180°C fan-forced (400° Fahrenheit/Gas 6). Bake until the top and base of the Schiacciata is browned (approximately 40-50 minutes). Depending on the size of your oven, you may need to bake the Schiacciate one at a time.
Slice and serve immediately or prepare in advance and reheat – buon appetito.
Note: Use a good quality, fruity extra virgin olive oil.
2 tablespoons (40g) extra virgin olive oil, plus extra to drizzle |1 clove garlic, crushed|600g broccoli, cut into small florets|300g Italian pork and fennel sausages, skin removed|10 capers, rinsed under cold water and drained, finely chopped|6 large basil leaves, finely chopped|200g Italian passata (or alternatively Italian canned chopped tomatoes)|250 g Caciocavallo cheese|50g Parmigiano Reggiano cheese|Sesame oil|Sea salt, freshly ground black pepper