1) Preheat the oven to 200°C/gas mark 6.
2) Place a baking rack on a sheet tray and lay the rasher bacon on the rack. Roast the bacon for about 20 minutes, until nicely browned. Allow to cool.
3) In a large bowl, toss together the rocket, apple, walnuts, cranberries and blue cheese.
4) For the dressing, whisk together the vinegar, orange zest, orange juice, mustard, maple syrup, 1 1/2 teaspoons of salt and the pepper in a bowl. Slowly whisk in the olive oil.
5) Chop the bacon into large pieces and add it to the salad. Toss the salad with just enough dressing to moisten. Sprinkle with 1/2 teaspoon of salt and toss well.