Preheat an oven to 425 degrees if cooking the broccolini, or skip this step if adding it raw.
Place the broccolini pieces in a single layer on a baking sheet with parchment paper or a silicone baking mat.
Cook for 15 minutes, and remove from the oven to allow to cool.
Spiralize the zucchini, and cut the long strings into shorter pieces to make it easier to eat.
Remove the pickled red onions from the jar and lay on a paper towel to remove any excess brine.
Place the zucchini noodles, cooled broccolini, red bell peppers, pickled red onions, and carrots into a large bowl.
Pour half the dressing over the ingredients, and use tongs to combine the ingredients and coat the salad in the dressing.
Add more dressing if desired, or serve additional dressing on the side.
To serve, add a serving to a bowl. Garnish with green onions, black sesame seeds, and microgreens if desired.