Thick-sliced king oyster mushrooms are seared until golden with a meaty, satisfying texture. This vegetarian, protein-rich dish is a healthy, low calorie family side with impressive umami depth.
Wipe king oyster mushrooms clean, trim ends, and slice lengthwise into thick ½-inch slices for best texture.
Heat 1 tbsp olive oil in a heavy skillet over medium-high until shimmering, then add mushrooms in a single layer. Sear undisturbed for 3 minutes until the bottom turns golden brown.
Flip the mushrooms and add onions and a pinch of salt. Continue cooking for 2-3 minutes, stirring occasionally, until onions become translucent and mushrooms are deeply browned.
Reduce heat to medium. Push vegetables to sides, add remaining olive oil and minced garlic to the center. Stir garlic 30 seconds until aromatic, then toss everything together.
Drizzle soy sauce and sesame oil evenly; add black pepper and scallions. Stir-fry for 1 minute to combine and allow sauce to reduce slightly. Serve hot.