1. Rinse brussels sprouts and remove any damaged or dirty outer leaves. Place on a cutting board and slice off the hard root end. Using a sharp knife, thinly slice the brussels sprouts. When you're done, use your fingers to gently separate the leaves so that the shredded sprouts resemble a very fine slaw. Place in a large bowl and set aside.
2. To toast the pecans, place a medium frying pan on the stove top. Turn on medium-high heat. When the pan is hot, add a single layer of pecans. Stir frequently with a spatula until they start looking darker and you can smell the toasted nuts. Remove from heat and spread out on a plate to cool to room temperature. Make sure you watch the pecans closely, they can burn pretty quickly and they will keep cooking after removing them from the pan.
3. While the pecans are cooling, make the dressing. In a small jar, add the olive oil, apple cider vinegar, Dijon mustard, salt, and pepper. Put a lid on the jar and shake until mixed well.
4. Add the toasted pecans, dried cranberries, and blue cheese to the chopped brussels sprouts. Pour the dressing over the salad and toss until all of the ingredients are well coated. Serve immediately.
Note-you can also use a mandoline or food processor to chop the brussels sprouts.