I made it last night. It's from Mark Bittman's Food Matters Cookbook.
From memory... cook one cup of brown rice (dry measurement). When it's done, stir in 1/3 cup miso paste, a tablespoon of grated ginger, two teaspoons of sesame oil, and a little bit of ground black pepper. The recipe calls for it to be served with broiled sliced eggplant and scallions, but suggests that portobello mushrooms or zucchini would work just as well.
I admittedly didn't measure carefully, but I would start with less miso next time. I might also thin it with a couple tablespoons of orange juice.