1.Preheat oven to 220°C Combine chicken, olive oil, garlic and tarragon in a large bowl and season.
2.Heat a large ovenproof frying pan over high heat, drizzle chicken with extra olive oil and fry until browned (2-3 minutes each side). Transfer to oven and roast until cooked through (3-5 minutes), then transfer to a plate, cover loosely with foil and rest for 5 minutes.
3.Meanwhile, bake prosciutto on an oven tray lined with baking paper until crisp (5-7 minutes). Break into pieces.
4.For fennel and cabbage salad, whisk olive oil, vinegar, garlic, lemon rind and juice and tarragon in a bowl. Add cabbage, fennel, shallot and herbs, toss to combine, season to taste and serve with chicken topped with shards of crisp prosciutto.