Adding to this super late but some red or orange pepper for color and flavor might work. Stirring in a handful of spinach could also work, or adding half a bigger tomato. I don't have a rice cooker so idk if they could go in while it's cooking, but they could easily be added afterwards. The pepper and tomato are getting a bit out of the 'low effort depression meal' though since you'd need to wash them and cut them up.

I've had this recipe on my mind for awhile now. Thanks for posting it! Not that my depression has been crippling lately (thankfully). It just sounds like a nice low effort recipe to try out. Unfortunately I'm usually not a low effort cook, so most of my ideas for veggie additions to this meal aren't as simple as 'just throw this in'. xD