In a large nonstick skillet (see note) over high or medium-high heat, sprinkle on a pinch of sea salt, and add the bell peppers or carrots, corn or green peas, green onions, and celery, stirring occasionally.
Cook for 3 to 4 minutes, then add the rice, potatoes (if using), and 1⁄4 cup of the tamari.
Cook for another 3 to 4 minutes, stirring a couple of times.
Add the water if the mixture is sticking. Heat the rice through, and toast it a little in spots, if desired. If using chives, add those and stir.
Taste, add the remaining tamari, and season with salt and black pepper, if desired. Serve.