The yellow grated mass on his tray is sauerkraut made with rutabaga (he is also eating roasted cauliflower and chicken). To make your own sauereuben, grate 5 pounds of rutabagas (or turnips). Sprinkle in 3 T of sea salt. Place into your fermentation vessel (or similar). Pound down to release the juices. Make sure the vegetables are covered with liquid, and place a ceramic plate (or similar) on top, touching vegetables. Weigh it down to keep it pressed against food (a quart mason jar filled with water works well). Cover entire vessel with a cheesecloth, dishtowel, or similar. Leave on the counter for 3-5 days. You can taste it to make sure the salt flavor is gone and it is tangy. That means those probiotics are there and the food is actually MORE nutritious than when you started. Refrigerate and enjoy!