Preheat the oven to 200°C.
Heat the duck legs on a tray in the oven for 10 minutes.
Melt sugar and cayenne pepper in a hot frying pan and swirl in 50ml of water.
Cook until a deep caramel forms, stir in pecans and salt, and bake on a tray for 5 minutes.
Whisk Gorgonzola and St Agur in a bowl, then mix in garlic, honey, buttermilk, and crème fraîche.
Whisk in lemon juice, Tabasco, Worcestershire sauce, vinegar, and mayonnaise, and season with salt and pepper.
Cool the duck and pecans slightly, then shred the duck meat from the bone.
Coat lettuce leaves with dressing, then toss with the shredded duck and caramelised pecans.
Serve the salad immediately in a large bowl.