Heat a pan over medium heat. Chop bacon and place in pan. Brown bacon and cook until crispy. Place cooked bacon on several folded paper towels to absorb the grease. Set aside.
While the bacon is cooking, prepare the veggies. Chop the broccoli into florets removing most of the stem and then coarsely chop. Add the broccoli to a large mixing bowl. Remove the core from the apple and dice in to ½ inch cubes and add to bowl. Thinly slice the green onions and the celery ribs and add both to the bowl.
Combine the ingredients for the dressing in a separate bowl and whisk together until smooth. Pour the dressing over the bowl of veggies, add walnuts and bacon and then stir together.
Serve immediately or store in the fridge in an airtight container for 1-2 days.