Preheat oven to 400 degrees Fahrenheit. Line a baking sheet with parchment or a Silpat. Using a box grater or food processor with a grating blade, grate the cauliflower, including both florets and stems. I cut my cauliflower into fourths to make it easier. Toss with 1 1/2 tablespoons melted coconut oil and 1/2 teaspoon salt. Spread cauliflower onto baking sheet and bake for 35-40 minutes, stirring twice throughout the baking. The cauliflower will shrink down a lot and begin to crisp a bit.
While the cauliflower cooks, toast the macadamia nuts. Place the macadamia nuts on a baking sheet and place in the oven with the cauliflower for 8-10 minutes. Because of their higher fat content, macadamia nuts cook a bit faster than other nuts so watch them carefully. Remove the nuts from the oven and very roughly chop.
Prepare the dressing. In a blender or mini food processor, place all of the dressing ingredients, except the cilantro and blend until smooth, scraping down the sides often. Add the cilantro, and pulse a few times until the cilantro has been incorporated.
Cook the soba noodles. Bring a pot of water to a boil. Add a pinch of salt to the water, then add the soba noodles, making sure they are all submerged. Cook for 3-4 minutes, testing the noodle for doneness. When you bite into it, you should see a tiny white speck, much like you find in an al dente Italian pasta noodle. Drain the noodles and immediately rinse under cold water to stop the cooking process.
Add the cooked soba to a bowl large enough for mixing. Toss in the roasted cauliflower pieces and the dressing. Sprinkle in half of the chopped macadamia nuts and mix everything together. Garnish the top with the remaining macadamia nuts and serve.