Fry ½ of the lardons until crisp, then drain on kitchen paper. Make up the dough following pack instructions then add the cooked lardons, chopped sage and grated cheese.
Oil a baking sheet, then press the dough into a 2cm-thick oval on it. Cover and rise in a warm place for 30 minutes, then cut 3 slashes into the dough and pull apart.
Scatter with the uncooked lardons, drizzle with olive oil, and bake at 220c/fan 200c/gas 7 for about 20 minutes until golden.