Pound chicken with a meat mallet between 2 sheets plastic wrap to an even 1cm thickness. Transfer to a large shallow dish, season with pepper and pour over buttermilk. Turn chicken to coat evenly.
Line a large baking tray with baking paper and spray with oil. Mix breadcrumbs, parmesan and Italian herbs on a large plate. Working with one chicken fillet at a time, remove from buttermilk, allow excess to drip off, then coat both sides in breadcrumb mixture. Place on prepared tray. Spray with oil.
Bake in a 220C oven (fan-forced) for 20 minutes, turning schnitzel halfway through cooking time, until lightly golden and cooked through.
Meanwhile, to make slaw, process broccoli in food processor until finely chopped. Transfer to a large heatproof bowl, cover with boiling water. Stand 2 minutes. Drain, rinse under cold water then drain well. Combine broccoli, cabbage, corn, shallots, basil and almonds in a large bowl.
Whisk buttermilk, mustard, parmesan and juice in a jug until combined. Add to slaw, season with pepper and toss well.
Divide slaw among 4 plates. Top with sliced schnitzel. Serve lemon wedges.

4 x 150g chicken breast fillets can be replaced with 2 x 300g fillets, cut horizontally through the side to give 4 thin pieces.
To make 1 cup breadcrumbs, process 2 x 35g slices wholegrain bread in a food processor. Use 1-2 day old bread for best results.
Broccoli slaw can be made up to 2 hours ahead. Keep, covered, in fridge.
Swap frozen corn with fresh kernels cut straight from the cob, if preferred.