In a medium saucepan, bring water to a boil. Add steel-cut oats, reduce heat to low, and simmer for 20-25 minutes until creamy but still chewy.
Meanwhile, heat olive oil in a skillet over medium heat. Add mushrooms and cook until they release their moisture and begin to brown, about 5-7 minutes.
Add garlic and ginger, cook for 30 seconds until fragrant. Add bok choy and cook until wilted, about 2 minutes.
In a small bowl, whisk together miso paste, tahini, and tamari with 2 tablespoons of warm water to create a sauce.
When oats are cooked, stir in the miso-tahini sauce.
Divide oats between bowls, top with the mushroom-bok choy mixture and a soft-boiled egg.
Garnish with scallions, sesame seeds, nori flakes, and a drizzle of chili oil.