Lapsang souchong tea gives this dish a subtle smoky flavor -- similar to that of dashi, a broth used in Japanese soups (including miso). For a heartier meal, add a poached egg or wedges of avocado on top.
Cut each wedge of squash crosswise into thirds. Combine with mushrooms and tea in a saucepan. Bring to a simmer; cook until squash is tender, about 10 minutes. Stir in sugar, soy sauce, and vinegar. Season with salt. For each serving, place 3/4 cup rice in a bowl; top with squash, mushrooms, 1/2 cup baby bok choy, and broth.