The olive juice in the dressing was inspired by my love of dirty martinis with blue cheese stuffed olives. It will work well on a picnic or a camping weekend if you slice the celery and grapes in advance and can toss the dressing in a mason jar. When you're ready to eat, just grate the apple, toss the dressing with the salad components, and top with nuts and cheese. While the olive juice is optional - if you leave it out it's a fairly typical vinaigrette - it's fairly acidic and you might want to increase the proportion of oil. —chezjewels
Put the minced shallot in the lemon juice to soak while you make the salad. Toast the pine nuts in a nonstick pan on the stove.
Prep the salad by slicing the celery into 1/4 inch pieces; quartering the red grapes; and grating the apple. Toss lightly together in a bowl.
Add the Dijon, olive juice (if using) and salt and pepper to the lemon juice and shallots. Mix well and taste for seasoning. Adjust the seasoning if needed, then whisk in the walnut oil. Pour about 1/4 cup over the salad and toss again lightly. Sprinkle the toasted pine nuts and crumbled blue cheese over and serve. You will have leftover dressing that will keep in the fridge for a few days.