Miso Mushroom Toast with Tahini Yogurt

Name: Miso Mushroom Toast with Tahini Yogurt
Prep time: 20 min
Cook time: 45 min
Total time: 45 min
Yield: 4 portions
Ingredients: 6 oz silken tofu; 6 oz plain yogurt; 1 ½ oz tahini; 1 tsp honey; 1 tsp vinegar; ½ tsp salt; ¼ tsp garlic powder; &frac18; tsp ground black pepper; 1 oz water; 14 oz fresh shiitake mushrooms; 1 oz salted butter; 2 tsp mirin; 1 tsp soy sauce; 1 tsp kecap manis; 1 tbsp red miso (or akamiso); 1 pinch ground white pepper; 4 slices sourdough bread