Tofu is pickled in a sweet and tangy brine with apple cider vinegar, crushed garlic, black peppercorns, sugar and salt then it's topped with a bit of mayo and Dijon mustard sauce.
Preheat oven to 375 degrees. Scrub beets and wrap in foil. Put in a small pan and roast for 1 hour. Remove from oven, unwrap carefully, and let cool. When cool, remove skins. Cut into 1 inch cubes. Set aside.
While beets are roasting, bring water, apple cider vinegar, peppercorns, salt, sugar, and garlic to a boil, stirring so all salt and sugar is dissolved. Remove from heat and let cool.
When beets and liquid are ready after cooling, layer beets, onion, and tofu in a large glass jar. Pour liquid over the top and let sit at room temperature, uncovered, for one hour. Then cover and refrigerate overnight.