Mix the sauce ingredients (vegetable broth, light soy sauce, dark soy sauce, sugar, black pepper, and sesame oil) in a small bowl and set aside.

In another small bowl, add the cornstarch and water to make a slurry. Stir to mix well and set aside.

Heat 1/4 cup of water in a large skillet over medium-high heat. When the water starts to boil, add the broccoli and sprinkle with a pinch of salt. Cover the pan and let steam for 1 minute.

After a minute, uncover the pan and stir. Cook until the broccoli is al dente and the water has evaporated. Once done, transfer the broccoli to a big plate.

Wipe the pan clean with paper towels. Add 2 tablespoons of peanut oil and turn the heat to high.

Add the sliced mushrooms. Let them sear without touching for 1 minute. Then flip the mushrooms and cook for another 2 to 3 minutes, stirring occasionally, until they are browned and cooked through.

Move the mushrooms to one side of the pan. Pour the remaining 1/2 tablespoon of oil on the other side and add the dried chili peppers, garlic, ginger, and green onions. Stir this mixture a few times until the chili peppers turn dark red. Then stir everything together.

Add the broccoli back into the pan. Pour in the prepared sauce and cook for 30 seconds while stirring.

Stir the slurry mixture again until the cornstarch is fully dissolved and swirl it into the pan. Cook and stir until the sauce thickens.

Transfer everything to a big plate and serve hot, either as a side dish or over steamed rice for a main course.