Cook the rice according to the package directions.
Meanwhile, heat the oil in a saucepan over medium-high heat.
Add the onion, bell pepper, garlic, 1 teaspoon salt, and ¼ teaspoon pepper and cook, stirring occasionally, until softened, 5 to 7 minutes.
Stir in the cumin and cook for 1 minute.
Add the beans, oregano, and 1 cup water. Simmer, covered, for 10 minutes.
Add the vinegar. Smash some of the beans with the back of a fork to thicken. Serve over the rice. Top with the radishes and cilantro.