Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion and green bell pepper. Sauté until softened, about 5-7 minutes.
Stir in the minced garlic, cumin, oregano, and black pepper. Cook for another minute until fragrant, being careful not to burn the garlic.
Add the undrained can of black beans and the bay leaf to the pot. Bring to a simmer and cook for about 10 minutes, allowing the flavors to meld. Mash a few beans against the side of the pot with your spoon to help thicken the mixture.
Stir in the cooked white rice and chopped cilantro. Mix well to combine everything evenly. Continue to cook, stirring occasionally, until the rice is heated through and has absorbed some of the bean liquid, about 5-7 minutes.
Remove the bay leaf before serving. Taste and adjust seasoning with salt as needed.
Garnish with fresh cilantro before serving.