Rub the okra with salt (not listed in ingredients) on a cutting board, then rinse with water and pat dry. Trim the tips and remove the calyx. Cut diagonally into thirds. Trim the root of the shimeji mushrooms and separate them.

Place the prepared okra and shimeji mushrooms in a microwave-safe container. Cover loosely with plastic wrap and microwave at 600W for 2 minutes. Drain the water, let cool slightly, and return to the container.