For the broccoli: Preheat oven to 375 F. Prepare the broccoli by cutting away and discarding the bottom of the stalk, then slicing lengthwise into "steak" pieces. Cut the pieces in half, then lengthwise again. Place in a large bowl and toss with salt, pepper, and grapeseed oil. Place on a rimmed baking sheet and roast in the oven, 15 minutes.
For the vinaigrette: In a small skillet, heat 1/2 tsp grapeseed oil and toast the pine nuts until lightly brown and aromatic, about 4 minutes. Remove from heat and add the peppercorns. Toss and set aside. In a food processor, blend the remaining grapeseed oil, shallots, ginger, and orange zest. While the motor is running, add the vinegar in a steady stream to combine; then taste to adjust the seasonings with salt and pepper. Scrape mixture into a bowl, and stir in sesame seeds, pine nuts, peppercorns, and scallions. Vinaigrette will be chunky.
Remove the caramelized broccoli from the oven to a mixing bowl and add the vinaigrette. Toss to coat and serve.