Combine the rice, butter, sesame oil, water, and a sprinkle of salt in a small saucepan. Bring to a boil and then stir once, cover, and reduce heat to very low. Cook for 16-18 minutes or until all the water is absorbed. Turn off the heat and rest the rice for 5-10 minutes before fluffing with a fork.

In a skillet or a wok, heat the neutral cooking oil over medium-high until hot. Once shimmering and very hot, add the sweet potato and cook, flipping occasionally, until well-browned all over and almost fork tender, about 8-10 minutes. Add the sliced pepper along with the Chinese Five Spice and the sesame oil and toss to coat. Cook an additional 4-5 minutes until completely cooked through. Transfer to a bowl and keep warm.

Keep the heat on the skillet or wok at medium and add the 1 tablespoon neutral cooking oil. Once hot, add the sliced shiitake mushrooms. Cook, stirring regularly, for 6-8 minutes or until the mushrooms begin to turn golden brown. If more liquid is needed, add a splash of water to release any browned bits stuck to the skillet.

Once the mushrooms have released and re-absorbed any liquid in the skillet and they are golden brown, add the soy sauce and water and scrape up any browned bits stuck to the bottom. Turn the heat to low and cook an additional 5-7 minutes, tossing the mushrooms in the sauce periodically. Add more liquid as necessary and to taste (soy sauce or water). Taste and season with salt and pepper, if needed. Transfer the mushrooms and any liquid to a bowl and keep warm.