How to Make It
Combine apple cider vinegar, Dijon mustard, honey, kosher salt, and black pepper in a small bowl. Bring water and Broccolini to a boil in a large saucepan over medium-high; cover and cook 5 minutes or until tender. Drain; rinse with cold water. Drain.
Combine Broccolini, matchstick-cut carrots, julienne-cut golden beet, thinly sliced red onion, and toasted sunflower seeds in a large bowl. Add vinegar mixture; toss. Let stand 10 minutes.