Heat 2 tsp. oil in medium pot over medium-high heat. Add onions and peppers; cook until soft, about 10 minutes. Add garlic, adobo, sugar and oregano, cook until fragrant, about 1 minute more.
Transfer liquid from can black beans to measuring cup; add enough water to measure 2 cups. Add liquid and bay leaf to pot; bring liquid to boil. Stir in black beans and rice. Bring rice mixture to boil. Reduce heat to medium-low. Simmer, covered, until rice absorbs water, about 25 minutes. Add vinegar; stir to combine.
Remove rice from heat; let sit until rice is tender, about 5 minutes more.
Evenly divide rice among serving bowls; drizzle with 1 tsp. olive oil.
If you’re tempted to toss leftover rice for fear the grains will dry out when reheated, try this trick to guarantee better-than-ever leftovers:
1. Transfer rice to container with tight-fitting lid. (Rice can be stored in container for up to 3 days).
2. To reheat, spoon rice into microwave-safe bowl. Sprinkle rice with 2 tbsp. water per cup. Cover bowl tightly with plastic wrap; using tip of knife, poke small hole in plastic. Microwave on high, until hot (one minute for every cup).
This steamy environment coaxes moisture into the grains and helps to revive the soft, tender texture of the rice.