Preheat oven to 200°C. Line a baking sheet with parchment paper. Tear bread into small chunks, add olive oil, finely grate 20 g Parmesan cheese, season with salt and freshly ground black pepper and toss to coat. Bake for 10-15 minutes, until golden-brown, tossing occasionally.
Roast chicken breast or thighs at 200°C for 20-30 minutes or until the internal temperature reaches 75°C. Let it sit for 5 minutes, then slice it.
To make the dressing, crush garlic until it forms a paste, then mash in the anchovies. Finely grate 10 g Parmesan cheese, then add lemon juice, mayo and mustard. Mix and gradually stir in 4 tbsp olive oil.
To assemble the salad, tear lettuce leaves into bite sized pieces into a large salad bowl, add in chicken, croutons, shaved Parmesan and drizzle with most of the dressing. Toss everything together and top with the remaining dressing and season with freshly ground black pepper.