Heat a large pan (or medium pot) over medium heat and drizzle with oil.
Add the diced red onion and sauté until golden and fragrant.
Stir in the sliced green bell pepper and minced garlic. Cook for 1-2 minutes until softened.
Add the drained black beans, cumin, and salt. Mix well to combine.
Stir in the rinsed jasmine rice, ensuring the grains are well coated.
Pour in the water or vegetable broth and bring the mixture to a boil.
Reduce the heat to low, cover with a lid, and let it simmer for 15 minutes, stirring halfway through to prevent sticking.
Once the rice is tender and the liquid is absorbed, add the black bean sauce for a rich black color and deeper flavor. Mix thoroughly.
Remove from heat, fluff with a fork, and serve warm.