Add the bacon to a medium saucepan and place over medium heat. Cook until crispy and the fat has rendered, about 7–9 minutes. Stir frequently.
Add the onion and cook for 2 minutes, stirring often.
Stir in the garlic and tomato paste. Cook for 30 seconds.
Add the black beans with their liquid, chicken broth, salt, oregano, cumin, black pepper, and bay leaf. Stir well.
Keep the heat at medium and bring the liquid to a simmer (this will take just a few minutes). Add the rice and stir well. Let it simmer uncovered for 5–7 minutes, or until some of the liquid has cooked out. You should see the rice on the surface; when stirred, it should no longer sink to the bottom. Stir occasionally to prevent sticking.
Lower the heat to low, cover, and cook for 22–25 minutes, or until the rice is tender and the liquid is absorbed. Stir once halfway through cooking, gently folding the rice from the bottom to the top.
Remove from the heat and let it sit, covered, for 5 minutes. Fluff with a fork, remove the bay leaf, and serve.
Notes
Green bell pepper is a traditional ingredient in moros, but it can easily overpower the dish. We prefer to go without. If using, add just ¼ pepper (seeded and finely diced) with the onion to sauté.
Rinse the rice well until the water runs clear to remove excess starch and prevent gumminess.
Use a non-stick or well-seasoned saucepan to reduce the risk of sticking.
Use low-sodium broth and/or beans if you're sensitive to salt.