Pour the pine nuts into a skillet. Toast the nuts over medium heat for about 2 to 3 minutes, until they start brown. Make sure to stir frequently to keep the pine nuts from burning. Transfer the nuts to a bowl to stop them from browning further. Set aside 2 teaspoons of toasted pine nuts for topping the dip.
Pour the Sichuan peppercorns into a bowl. Pick out any small twigs or tiny black seeds. The seeds are bitter and inedible, so don’t bother grinding them.
Using a pestle and mortar, grind the Sichuan peppercorns until they turn into powder and you can no longer grind the husks any further. The husks won’t break down further and have a tough texture.
Sift out the husks through a mesh strainer. You should now have about 1 1/2 teaspoons of ground peppercorn powder. I am pretty spice tolerant, so I used all 1 1/2 teaspoons of the peppercorn powder. The dip has a noticeable tongue-tingling sensation, but it’s not insanely spicy. If you are more spice averse, feel free to use less of the peppercorn powder in the next step or skip it entirely. (See note 4 about using pre-ground Sichuan peppercorns.)
Transfer the rinsed cannellini beans to the bowl of a food processor. Add the toasted pine nuts, ground peppercorn, olive oil, soy sauce, lemon juice, and salt.
Start blending everything together. If ingredients are getting stuck to the sides of the bowl, turn off the food processor and scrape down the sides. Stream in 2 tablespoons of ice water and keep blending the dip. I like using 2 1/2 tablespoons of water for a creamier dip, but feel free to use less water. Taste the bean dip and add more salt, if desired. (Note: my chili oil recipe contains salt, so you might not need to add more here.)
Transfer the white bean dip to a serving bowl. Use the back of the spoon to create a spiral pattern on the bean dip. Spoon the chili oil, especially the solids, over the bean dip (I usually use about 1 1/2 to 2 tablespoons of the chili oil). Top with reserved toasted pine nuts and sliced scallions. Serve the bean dip with vegetables, crackers, or pita! Refrigerate any leftovers for up to 5 days.