This is based on a dish I serve at Marion in Melbourne. If you can find yellow (butter) beans, use them instead of green or use a combination of the two.
400g green beans, trimmed
1 tsp olive oil
1 shallot (French eschalots), finely diced
½ bunch tarragon, roughly chopped
25g dijon mustard
30ml white wine vinegar
30ml olive oil
50ml grapeseed oil
1. Preheat oven to 160C (140C fan-forced).
2. Bring a large pot of water to the boil and season with a pinch of salt. Prepare a bowl of iced water on the side for cooling the beans. Blanch the beans for 60 seconds in the boiling water. Remove and place in the ice bath to arrest the cooking process. Once cold, remove from the ice bath and drain on paper towels.
3. Place the hazelnuts on a baking tray and roast for 8 minutes or until lightly golden (you should see the skin beginning to crack). Allow to cool slightly. While the nuts are still warm, rub the hazelnuts with a clean tea towel to remove the skins. Chop coarsely and set aside.
4. Heat a barbecue or chargrill pan to medium heat. Toss the blanched beans in the olive oil. Place the beans on the barbecue and cook, moving constantly with your tongs, until they are well charred (not black) and smoky. Remove from heat and set aside to cool to room temperature.
5. To make the dressing, put the mustard and vinegar in a bowl and whisk to combine. Slowly add the olive and grapeseed oils while whisking to create an emulsion. Season with salt and pepper.
6. Combine the beans, hazelnut, shallot, tarragon and dressing in a bowl. Season to taste. Arrange the bean salad on a platter. Using a vegetable peeler, shave curls of the manchego across the top of the salad. Serve immediately.