Miso Mushrooms Toast with Tahini Yogurt

Name: Miso Mushrooms Toast with Tahini Yogurt
Prep time: 20 min
Cook time: 45 min
Total time: 45 min
Yield: 4 portions
Ingredients: 170 g silken tofu, any type; 170 g plain yogurt; 45 g tahini; 1 tsp honey; 1 tsp vinegar; ½ tsp salt; ¼ tsp garlic powder; &frac18; tsp black pepper, ground; 30 g water; 395 g shiitake mushroom, fresh; 30 g butter, salted; 2 tsp mirin; 1 tsp soy sauce; 1 tsp sweet soy sauce (Kecap Manis); 1 tbsp red miso paste (or akamiso); 1 pinch white pepper, ground; 4 slices sourdough bread