Very finely slice the cedro with a mandolin (use the guard!) and place in a large bowl along with the juice of the lemon. Add the mint, rocket and chilli, followed by a good lug of extra virgin olive oil and put to one side.
Place a griddle pan over a high heat and toast the soughdough for around 3 to 4 minutes, or until nicely bar-marked and golden, turning halfway. Using tongs, remove the toasted sourdough to a serving board, then halve the garlic clove and rub all over one side of the bread. Drizzle over a little extra virgin olive oil, halve the tomatoes and rub into the bread, then tear over the mozzarella.
Season the cedro salad to taste, then toss well to combine and pile onto the bruschetta. Serve right away.