I saw this while looking for something else and had to try it.  Nice variation.  Even dressed it kept for several days.

“Here’s how I get this salad ready for picnics, potlucks, and other summer flings: I prepare the cabbage and carrots and keep them in a big container or gallon bag. I make the dressing and keep it in a big jar. And when needed, I assemble what we need with chopped parsley. The parsley doesn’t add a significant flavor, but it does make the salad look like a show-stopper. You could also use ribbons of kale for a modern twist. I don’t use the blue cheese as often, but if you’ve got friends and family who like it, they will love it here.”

The prepared vegetables without dressing will keep for 5 days in a bag. The dressing without blue cheese keeps… well, I can’t say forever, but there’s honestly not one thing in there that shouldn’t keep for a month or two. We keep it in an airtight jar in the fridge. With blue cheese, I’d use it within a week.

Ingredients:

• 2 c mayonnaise, low-fat is fine, as is swapping half with yogurt
• 1/4 c  smooth Dijon mustard
• 3 Tab whole grain mustard
• 2 Tab apple cider vinegar
• 1 tsp celery seed
• 1/2 tsp kosher salt
• 1/2 tsp freshly ground black pepper
• 1 1/2 c (6 ounces) crumbled blue cheese (optional)
• 1/2 of a small head (about 15 ounces for half) green cabbage
• 1/2 small (13 ounces for half) head red cabbage
• 1 giant carrot (about 6 ounces) or 4 slim ones, scrubbed or peeled and shredded
• 1 c chopped fresh parsley leaves or 1 cup slivered kale leaves

Directions – dressing:

1. Mix the mayonnaise, mustards, vinegar, celery seed, salt, and pepper in a small bowl.
2. Stir in blue cheese, if using.

Directions – Salad:

1. Halve the cabbage halves and cut out the cores.
2. Slice the cabbage as thinly as you can with a sharp knife, or on a mandoline.
3. Transfer chopped cabbage into a large bowl or Ziploc bag.
4. Stir in the shredded carrot. (If you’re going to dress this later, this is the best stopping point.)
5. Up to an hour before you’ll eat the slaw, toss the cabbage mixture with dressing to taste –- you will want to start with half and add more as needed — and parsley.
6. Adjust seasonings as needed.

Note: No matter how gargantuan the salad looks right now, it will soon wilt down a bit and yield moderate portions for 8 to 10 people.

Serves: 8 – 10

Source:  Smitten Kitchen from Ina Garten