Heat the oven to 425°F. Set a medium saucepan with a lid and a large skillet on the stove, and set out a sheet pan for the broccoli.

Rinse the rice in a fine-mesh sieve under cold water until the water looks mostly clear instead of cloudy.

Put the rice, 2 1/4 cups of the water, and 1/2 teaspoon of the salt into the saucepan. Bring it to a boil over high heat.

As soon as the water boils, cover the saucepan and turn the heat to low. Cook for 15 minutes, then move the pan off the heat and let it sit covered for 5 minutes.

While the rice cooks, put the broccoli florets on the sheet pan. Drizzle them with 1 tablespoon of the oil and sprinkle with the remaining 1/2 teaspoon salt.

Toss the broccoli on the sheet pan so it is evenly coated, then spread it into a single layer. Roast for 18 to 22 minutes, stirring once halfway through, until the broccoli is tender and the edges have dark brown spots.

Put the white miso, soy sauce, rice vinegar, and remaining 1/2 cup water into a small bowl. Whisk until the miso dissolves and the sauce looks smooth.

Slice the scallions if you have not already, and keep the white parts and green parts in separate piles so they are easy to use at different times.

Pour the remaining 1 tablespoon oil into the large skillet and warm it over medium heat.

Add the scallion whites and the grated ginger to the skillet. Cook for about 1 minute, stirring often, until they smell fragrant and soften slightly.

Add the drained butter beans to the skillet. Stir gently for 1 minute so the beans warm through without breaking apart too much.

Pour the miso mixture into the skillet with the beans. Bring it to a gentle simmer over medium-low heat.