Heat oil in medium saucepan over medium heat. Add chopped onions and cook until translucent, about 3 minutes. Add diced garlic, bell peppers, and jalapenos and cook for another minute.
Add canned black beans, vegetable stock, cumin, and garlic powder. Bring to a boil then reduce heat to a simmer. Simmer for 10 minutes, until most of the stock evaporates. Using a fork, mash up some of the beans in the pot to thicken the sauce. Stir in salt, pepper, and lime juice. Remove from heat and add chopped cilantro.
Baked Plantain: Peel plantain and cut diagonally into 1in thick slices. Place plantain slices on greased baking sheet. Bake for 20 minutes in 350 degree F oven, turnng halfway through.
Serve black beans with cooked quinoa and baked plantain. Top with fresh cilantro. Enjoy!